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How secure is 256 bit security?
 
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Supplement to the cryptocurrency video: How hard is it to find a 256-bit hash just by guessing and checking? What kind of computer would that take? Cryptocurrency video: https://youtu.be/bBC-nXj3Ng4 Thread for Q&A questions: http://3b1b.co/questions Several people have commented about how 2^256 would be the maximum number of attempts, not the average. This depends on the thing being attempted. If it's guessing a private key, you are correct, but for something like guessing which input to a hash function gives a desired output (as in bitcoin mining, for example), which is the kind of thing I had in mind here, 2^256 would indeed be the average number of attempts needed, at least for a true cryptographic hash function. Think of rolling a die until you get a 6, how many rolls do you need to make, on average? Music by Vince Rubinetti: https://vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown ------------------ 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted on new videos, subscribe, and click the bell to receive notifications (if you're into that). If you are new to this channel and want to see more, a good place to start is this playlist: http://3b1b.co/recommended Various social media stuffs: Website: https://www.3blue1brown.com Twitter: https://twitter.com/3Blue1Brown Patreon: https://patreon.com/3blue1brown Facebook: https://www.facebook.com/3blue1brown Reddit: https://www.reddit.com/r/3Blue1Brown
Views: 1016122 3Blue1Brown
Cryptographic Hash Functions - CompTIA Security+ SY0-401: 6.2
 
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Security+ Training Course Index: http://professormesser.link/sy0401 Professor Messer’s Course Notes: http://professormesser.link/sy0401cn Frequently Asked Questions: http://professormesser.link/faq - - - - - There are many hash functions for many different circumstances. In this video, you’ll learn about MD5, SHA, RIPEMD, and HMAC hash functions. - - - - - Download entire video course: http://professormesser.link/401adyt Get the course on MP3 audio: http://professormesser.link/401vdyt Subscribe to get the latest videos: http://professormesser.link/yt Calendar of live events: http://www.professormesser.com/calendar/ FOLLOW PROFESSOR MESSER: Professor Messer official website: http://www.professormesser.com/ Twitter: http://www.professormesser.com/twitter Facebook: http://www.professormesser.com/facebook Instagram: http://www.professormesser.com/instagram Google +: http://www.professormesser.com/googleplus
Views: 42081 Professor Messer
ERC20 tokens - Simply Explained
 
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Not all cryptocurrencies have their own blockchains. Instead they run on top of other platforms like ERC20 tokens run on top of Ethereum. This video explains what these tokens are and why ERC20 was created. 📚 Sources Can be found on my website: https://www.savjee.be/videos/simply-explained/erc20-tokens/ 🌍 Social Twitter: https://twitter.com/savjee Facebook: https://www.facebook.com/savjee ✏️ Check out my blog https://www.savjee.be
Key Exchange Problems - Computerphile
 
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Diffie Hellman has a flaw. Dr Mike Pound explains how a man in the middle could be a big problem, unless we factor it in... Public Key Cryptography: https://youtu.be/GSIDS_lvRv4 Elliptic Curve Cryptography: Coming Soon! https://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: https://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 122828 Computerphile
NETWORK SECURITY - BLOCK CIPHER MODES OF OPERATION
 
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1. Electronic Code Book Mode 2. Cipher Block Chaining Mode 3. Output Feedback Mode 4. Cipher Feedback Mode 5. Counter Mode
Hashing Algorithms - CompTIA Security+ SY0-501 - 6.2
 
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Security+ Training Course Index: http://professormesser.link/sy0501 Professor Messer’s Course Notes: http://professormesser.link/501cn Frequently Asked Questions: http://professormesser.link/faq - - - - - There are many methods and implementations of cryptographic hashing. In this video, you’ll learn about some of the most popular hashing algorithms. - - - - - Subscribe to get the latest videos: http://professormesser.link/yt Calendar of live events: http://www.professormesser.com/calendar/ FOLLOW PROFESSOR MESSER: Professor Messer official website: http://www.professormesser.com/ Twitter: http://www.professormesser.com/twitter Facebook: http://www.professormesser.com/facebook Instagram: http://www.professormesser.com/instagram Google +: http://www.professormesser.com/googleplus
Views: 13701 Professor Messer
What is CRYPTOGRAPHIC NONCE? What does CRYPTOGRAPHIC NONCE mean? CRYPTOGRAPHIC NONCE meaning
 
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What is CRYPTOGRAPHIC NONCE? What does CRYPTOGRAPHIC NONCE mean? CRYPTOGRAPHIC NONCE meaning - CRYPTOGRAPHIC NONCE definition - CRYPTOGRAPHIC NONCE explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In cryptography, a nonce is an arbitrary number that may only be used once. It is similar in spirit to a nonce word, hence the name. It is often a random or pseudo-random number issued in an authentication protocol to ensure that old communications cannot be reused in replay attacks. They can also be useful as initialization vectors and in cryptographic hash function. A nonce is an arbitrary number used only once in a cryptographic communication, in the spirit of a nonce word. They are often random or pseudo-random numbers. Many nonces also include a timestamp to ensure exact timeliness, though this requires clock synchronization between organizations. The addition of a client nonce ("cnonce") helps to improve the security in some ways as implemented in digest access authentication. To ensure that a nonce is used only once, it should be time-variant (including a suitably fine-grained timestamp in its value), or generated with enough random bits to ensure a probabilistically insignificant chance of repeating a previously generated value. Some authors define pseudo-randomness (or unpredictability) as a requirement for a nonce. Authentication protocols may use nonces to ensure that old communications cannot be reused in replay attacks. For instance, nonces are used in HTTP digest access authentication to calculate an MD5 digest of the password. The nonces are different each time the 401 authentication challenge response code is presented, thus making replay attacks virtually impossible. The scenario of ordering products over the Internet can provide an example of the usefulness of nonces in replay attacks. An attacker could take the encrypted information and—without needing to decrypt—could continue to send a particular order to the supplier, thereby ordering products over and over again under the same name and purchase information. The nonce is used to give 'originality' to a given message so that if the company receives any other orders from the same person with the same nonce, it will discard those as invalid orders. A nonce may be used to ensure security for a stream cipher. Where the same key is used for more than one message and then a different nonce is used to ensure that the keystream is different for different messages encrypted with that key; often the message number is used. Secret nonce values are used by the Lamport signature scheme as a signer-side secret which can be selectively revealed for comparison to public hashes for signature creation and verification. Initialization vectors may be referred to as nonces, as they are typically random or pseudo-random. Nonces are used in proof-of-work systems to vary the input to a cryptographic hash function so as to obtain a hash for a certain input that fulfills certain arbitrary conditions. In doing so, it becomes far more difficult to create a "desirable" hash than to verify it, shifting the burden of work onto one side of a transaction or system. For example, proof of work, using hash functions, was considered as a means to combat email spam by forcing email senders to find a hash value for the email (which included a timestamp to prevent pre-computation of useful hashes for later use) that had an arbitrary number of leading zeroes, by hashing the same input with a large number of nonce values until a "desirable" hash was obtained. Similarly, the bitcoin block-chain hashing algorithm can be tuned to an arbitrary difficulty by changing the required minimum/maximum value of the hash so that the number of bitcoins awarded for new blocks does not increase linearly with increased network computation power as new users join. This is likewise achieved by forcing bitcoin miners to add nonce values to the value being hashed to change the hash algorithm output. Because cryptographic hash algorithms cannot easily be predicted based on their inputs, this makes the act of blockchain hashing and the possibility of being awarded bitcoins something of a lottery, where the first "miner" to find a nonce that delivers a desirable hash is awarded valuable bitcoins.
Views: 6269 The Audiopedia
Cryptographic hash function
 
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A cryptographic hash function is a hash function which is considered practically impossible to invert, that is, to recreate the input data from its hash value alone. The input data is often called the message, and the hash value is often called the message digest or simply the digest. This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 2389 Audiopedia
Secrets Hidden in Images (Steganography) - Computerphile
 
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Secret texts buried in a picture of your dog? Image Analyst Dr. Mike Pound explains the art of steganography in digital images. The Problem with JPEG: https://youtu.be/yBX8GFqt6GA The Bayer Filter: https://youtu.be/LWxu4rkZBLw Super Computer & the Milky Way: https://youtu.be/5KEhhW8TOGk JPEG Discrete Cosine Transform (DCT): https://youtu.be/Q2aEzeMDHMA http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 645296 Computerphile
The Golden Key: FBI vs Apple iPhone - Computerphile
 
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Should Apple unlock a terrorists iPhone for the FBI? Professor Ross Anderson explains how this is a "Pandora's Box" situation. Buffer Overflow Attacks: https://youtu.be/1S0aBV-Waeo $5 Computer: https://youtu.be/WR0ghM3U0M4 AI Safety: https://youtu.be/IB1OvoCNnWY EXTRA BITS: https://youtu.be/6iGxNku7ilw http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 274265 Computerphile
Excel - Encryption using Excel      ( Great Trick )
 
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Many more great Excel tutorials linked below: http://www.youtube.com/playlist?list=PL8004DC1D703D348C&feature=plcp Be sure to watch my other Excel tutorial videos on my channel, including more advanced techniques and many useful and practical ones. Be sure to Subscribe and Comment.
Views: 31164 Jalayer Academy
Applied Cryptography: The RSA Digital Signature - Part 1
 
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This video gives an overview of the RSA Digital Signature. It shows how this scheme is closely related to RSA encryption/decryption.
Views: 7357 Leandro Junes
symmetric key cryptography
 
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https://8gwifi.org/CipherFunctions.jsp Reference book: http://leanpub.com/crypto Cryptographic Algorithms generally fall into one of two different categories, or are a combination of both. Symmetric Fast Only provide confidentiality Examples: DES, AES, Blowfish, RC4, RC5 Asymmetric Large mathematical operations make it slower than symmetric algorithms No need for out of band key distribution (public keys are public!) Scales better since only a single key pair needed per individual Can provide authentication and nonrepudiation Examples: RSA, El Gamal, ECC, Diffie-Hellman problem with symmetric key cryptography DES (Data Encryption Standard) 64 bit key that is effectively 56 bits in strength Actual algorithm is called DEA (Data Encryption Algorithm) DES Modes Electronic Code Book Cipher Block Chaining (most commonly used for general purpose encryption) Cipher Feedback Output Feedback Counter Mode (used in IPSec) 3DES 112-bit effective key length Uses either 2 or 3 different smaller keys in one of several modes Modes EEE2/3 EDE2/3 AES NIST replaced DES in 1997 with this Uses the Rijndael algorithm Supports key/block sizes of 128, 192, and 256 bits Uses 10/12/14 rounds as block size increases IDEA (International Data Encryption Algorithm) Operates on 64 bit blocks in 8 rounds with 128 bit key Considered stronger than DES and is used in PGP Blowfish 64 bit block cipher with up to 448 bit key and 16 rounds Designed by Bruce Schneier RC4 Stream cipher with variable key size created by Ron Rivest RC5 Another Rivest cipher Block cipher with 32/64/128 bit blocks and keys up to 2048 bits RC6 Beefier version of RC5 submitted as AES candidate CAST 64 bit block cipher with keys between 40-128 bits with 12-16 rounds depending on key length CAST-256 used 128-bit blocks and keys from 128-256 bits using 48 rounds SAFER (Secure and Fast Encryption Routine) Set of patent-free algorithms in 64 and 128 bit block variants Variation used in Bluetooth Twofish Adapted version of Blowfish with 128 bit blocks, 128-256 bit keys and 16 rounds AES Finalist Kryptografie mit symmetrischem Schlüssel symmetric key cryptography symmetric key cryptography tutorial symmetric key cryptography example symmetric key cryptography vs asymmetric key cryptography symmetric and asymmetric key cryptography symmetric key cryptography Kryptografie mit symmetrischem Schlüssel Kryptographie mit symmetrischem Schlüssel Kryptographie mit symmetrischem Schlüssel Kryptografie mit symmetrischem Schlüssel und asymmetrische Schlüsselkryptographie symmetrische und asymmetrische Schlüsselkryptographie Kryptografie mit symmetrischem Schlüssel
Views: 41420 Zariga Tongy
ripemd 160
 
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RIPEMD 160 hash algorithm https://hash.onlinetoolsland.com/ripemd/ The whole name of RIPEMD is RACE Integrity Primitives Evaluation Message Digest. RIPEMD a family of cryptographic hash functions developed by Hans Dobbertin, Antoon Bosselaers and Bart Preneel RIPEMD is published in 1996. RIPEMD-160 is an improved version of the original RIPEMD RIPEMD-160 has a 160-bit length ,and is the most common used version in the RIPEMD family. there are 128, 256 and 320-bit versions of RIPEMD algorithm,RIPEMD-128 is designed to replacement for the original RIPEMD. In 2004, a hash collision was reported for the original RIPEMD algorithm . The RIPEMD-160 hash algorithm is open to the public from the beginning , unlike the sha-1 and sha-2 algorithms. Which is developed by the NSA. https://hash.onlinetoolsland.com/ripemd/ The RIPEMD-160 hash algorithm is not used as frequently as the SHA-1 algorithm , but it is not get constrained by any patents. The 128 bit RIPEMD-128 was invented as a replacement for the initial RIPEMD algorithm , the initial RIPEMD algorithm was also 128 bit, but the security of the original RIPEMD algorithm is questionable. The RIPEMD-256 and RIPEMD-320 versions only diminish the possibility of accidental collision, but their security level is not as high as the RIPEMD-128 and RIPEMD-160 algorithm . The RIPEMD-160 hash algorithm contain 160bit data, which is also known as the RIPE message digests, the 160 bit data is represented as 40-digit hexadecimal numbers. The following data show us a 43 byte length of ascii input and the result RIPEMD-160 hash: RIPEMD-160("The quick brown fox jumps over the lazy dog") = 37f332f68db77bd9d7edd4969571ad671cf9dd3b The RIPEMD-160 also act just with the avalanche effect which is common in all cryptographic hash functions (small changes, e.g. changing d to c, result in a completely different hash) RIPEMD-160("The quick brown fox jumps over the lazy cog") = 132072df690933835eb8b6ad0b77e7b6f14acad7 The RIPEMD hash is a collection of several cryptographic hash functions. It compete with the MD hash family and the SHA hash family. The original RIPEMD hash algorithm is designed as a variation of the md4 hash algorithm , in fact there are 2 MD4 algorithm. The RIPEMD algorithm is not as efficient as the MD5 hash algorithm. And because it is based on MD4 , there are some doubt that is also contain some weakness that the MD4 hash algorithm has, for example the collisions flaw Because the concerns, the author of the RIPEMD make a new hash algorithm called the RIPEMD-160. The RIPEMD-160 algorithm is quite good, and robust. Compare the permance between the sha 1 and RIPEMD-160 , the RIPEMD-160 is a bit slower ,so it is not used widely as the SHA-1 algorithm. One of the main useage for the RIPEMD-160 is inside the PGP. That is because as a sign of defiance against governmental agencies, the pgp chose the RIPEMD-160 over SHA-1 hash algorithm The RIPEMD-256 is a 256-bit version of RIPEMD-160 algorithm, but it is not widely used compare to the sha hash family such as the sha 2. So this is why the RIPEMD hash algorithm is not widely used. The difference the RIPEMD-160 or RIPEMD-256 algorithm Some people will ask which RIPEMD hash to use, the RIPEMD-160 or RIPEMD-256. At first glance , the RIPEMD-160 seems a quite good hash algorithm, but as the growth of current computing .the RIPEMD-160 output is a bit short. (if you want to generate encryption with 128-bit keys, you should, go for the hash algorithm functions with 256-bit output) and the RIPEMD-160 computing speed is not very good compare to other same level algorithm, so may be you can get better performance if you go with the SHA-256, which has more optimized implementations The RIPEMD-256 implementation is a new one compare to its cousins . but it is not quite popular, not many reaserch have done on it , so you should take more caution, if you want to use it on your commercial product. Since the 128 bit hash result no longer stand against the brutal force collision attack At Crypto 2004 several Chinese crypto scientists announced that they found collisions for MD4, MD5, RIPEMD, and the 128-bit version of HAVAL. So the RIPEMD-160 is designed as a improved version of the RIPEMD-128 hash result. And is expected to be secure for the next ten years or more. https://hash.onlinetoolsland.com/ripemd/ The RIPEMD -160 is tuned for the 32-bit processors. The RIPEMD-256 and RIPEMD-320 hash algorithm are extensions of RIPEMD-128 and RIPEMD-160. They are designed as a longer hash result without the need of a larger security level. Where can I find a detailed description of RIPEMD-160 hash algorithm
Views: 122 video video
Elliptic Curve Cryptography & Diffie-Hellman
 
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Today we're going over Elliptic Curve Cryptography, particularly as it pertains to the Diffie-Hellman protocol. The ECC Digital Signing Algorithm was also discussed in a separate video concerning Bitcoin's cryptography.
Views: 53321 CSBreakdown
Hashing Searching Sketching.
 
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Google Tech Talks November 20, 2006 ABSTRACT We will see improved results on search using hashing and sketching. Hashing is often analyzed as balls being thrown into bins where you think of the hash items as balls and buckets as bins. By studying variants of the balls and bins processes we obtain a hashing algorithm with 85% hash table space utilization. We will also study locality sensitive hashing, a hashing method used for nearest neighbor search, as opposed to exact search. A locality sensitive hash function is likely to map nearby elements to the same bucket. We will see a variant of locality sensitive hashing that finds an approximate nearest neighbor in high dimensions using linear space. We...
Views: 13969 GoogleTechTalks
Cryptography, Cryptographic Security Controls & Cryptography Security Techniques Explained
 
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Thanks For Watching This Video, I Hope You Must Have Liked It. If yes then please hit the subscribe button as I will be uploading a lot of IT security related training videos on this channel and if you will be my subscriber then you my friend will be the first one who will be notified about all my new videos my friend. If you have any questions for the topic that I have discussed in this video then please feel free to comment my friend and I will be happy to respond back to your queries... Please note that - all ISO 27001 documents and standards are completely owned intellectual property & copyright of ISO. So in case if by any chance you are interested to study more about the standard that I have discussed here then please go to the official ISO website in order to purchase the standards. This channel is only created to generate awareness and best practices for Information Security in general and if by any chance you wish to implement any of the standards that I have discussed here then you have to first purchase them from official ISO website. This channel is only created to help anyone who is currently studying or planning to study about ISMS Information Security Management System ISO 27001 Implementation. I want to make my contribution in the information security community.This channel is only created to generate awareness and best practices for Information Security in general. Disclaimer: Since ISO 27001 is a very vast topic and the implementation varies for all organization's so I can't ever call myself an "expert" in this field, all the knowledge and information that I am sharing here is only based upon my past experience in information security field and may not be directly applicable within your organization as such. So please use your judgement before implementing anything based upon my suggestions. I request you not to rely on anything that I say here, I do my best to be as accurate and as complete information that I can provide you “but” only the published standards are definitive. Only the published ISO standards stand above any information that I have shared in any of my videos. Thanks, Your IT Security Friend Luv Johar Website : http://aajkatech.com/ iso 27001 explained, iso 27001 awareness trainings, iso 27001 free trainings online, Iso 27001 free tutorials, ISO 27001 training material free, lead auditor free training course, lead implementer free training course, ISMS training free, information security management system training free,
Bitcoin - Digital Signatures
 
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A high-level explanation of digital signature schemes, which are a fundamental building block in many cryptographic protocols. More free lessons at: http://www.khanacademy.org/video?v=Aq3a-_O2NcI Video by Zulfikar Ramzan. Zulfikar Ramzan is a world-leading expert in computer security and cryptography and is currently the Chief Scientist at Sourcefire. He received his Ph.D. in computer science from MIT.
Views: 141481 Khan Academy
IOTA tutorial 1: What is IOTA and some terminology explained
 
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If you like this video and want to support me, go this page for my donation crypto addresses: https://www.youtube.com/c/mobilefish/about Update: In this video i mentioned Curl and the vulnerability found in this algorithm. However it seems that this is NOT correct. Please read: https://blog.iota.org/official-iota-foundation-response-to-the-digital-currency-initiative-at-the-mit-media-lab-part-1-72434583a2 This is part 1 of the IOTA tutorial. In this video series different topics will be explained which will help you to understand IOTA. It is recommended to watch each video sequentially as I may refer to certain IOTA topics explained earlier. IOTA is not an acronym for Internet of Things, (IoT) but it just mean something very small. David Sønstebø, Sergey Ivancheglo, Dominik Schiener and Serguei Popov founded IOTA in 2015. IOTA Foundation main focus is Internet of Things and the Machine Economy but this technology is well suited for payments between humans as well. The IOTA white paper can be found at: https://iota.org/IOTA_Whitepaper.pdf All IOTA's which will ever exist have already been created.  The total IOTA supply is: 2,779,530,283,277,761 IOTAs IOTA features - Scalability The network becomes stronger when the number of transactions increases. IOTA can achieve high transaction throughput. - Decentralisation IOTA has no miners. Every transaction maker is also a transaction validator which means every transaction maker actively participates in the consensus. - No transaction fees IOTA has no transaction fees which means IOTA can be used for micropayments. - Quantum computing protection Quantum computers will be able to crack current data encryption methods much faster than current classical computers. IOTA uses the Winternitz One-Time Signature Scheme which is a quantum-resistant algorithm. See: https://eprint.iacr.org/2011/191.pdf IOTA is the 3rd generation public permissionless distributed ledger, based on a Directed Acyclic Graph (DAG). IOTA called this DAG the tangle. The tangle is NOT the same as the Blockchain. A tangle is a data structure based on Directed Acyclic Graph (DAG). Each transaction always validates 2 previous non validated transactions. Directed means the graph is pointing to one direction. Tips are the unconfirmed transactions in the tangle graph. Height is the length of the longest oriented path to the genesis. Depth is the length of the longest reverse-oriented path to some tip. Making a transaction is a 3 step process: - Signing: Your node (computer / mobile) creates a transaction and sign it with your private key. - Tip Selection: Your node chooses two other unconfirmed transactions (tips) using the Random Walk Monte Carlo (RWMC) algorithm. - Proof of Work: Your node checks if the two transactions are not conflicting. Next, the node must do some Proof of Work (PoW) by solving a cryptographic puzzle (hashcash). Hashcash works by repeatedly hashing the same data with a tiny variation until a hash is found with a certain number of leading zero bits. This PoW is to prevent spam and Sybil attacks. The goal of the Random Walk Monte Carlo algorithm is to generate fair samples from some difficult distribution. The Random Walk Monte Carlo (RWMC) algorithm is used in two ways: - To choose two other unconfirmed transactions (tips) when creating a transaction. - And to determine if a transaction is confirmed. To determine the confirmation level of your transaction we need the depth to start from and we execute the Random Walk Monte Carlo algorithm N times, the probability of your transaction being accepted is therefore M of N. M being the number of times you land on a tip that has a path to your transaction. If you execute RWMC 100 times, and 60 tips has a path to your transaction, than your transaction is 60% confirmed. It is up the the merchant to decide to accept the transaction and exchange goods. It is the same as Bitcoins where you want to wait for at least 6 blocks for high value transactions. Transactions with bigger depths takes longer to be validated. An IOTA Reference Implementation (IRI), wallet and libraries are available at: https://github.com/iotaledger To setup a full node you need to tether with neighbours by exchanging your ip address with theirs. Once you have sent a transaction from an address, you should never use this address again. A tangle can get branch off and back into the network. This is called partitioning. The Coordinator or ‘Coo’ for short, are several full nodes scattered across the world run by the IOTA Foundation. It creates zero value transactions called milestones which full nodes reference to. Check out all my other IOTA tutorial videos https://goo.gl/aNHf1y Subscribe to my YouTube channel: https://goo.gl/61NFzK The presentation used in this video tutorial can be found at: https://www.mobilefish.com/developer/iota/iota_quickguide_tutorial.html #mobilefish #howto #iota
Views: 36000 Mobilefish.com
USENIX Security '17 - Speeding up detection of SHA-1 collision attacks...
 
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Speeding up detection of SHA-1 collision attacks using unavoidable attack conditions Marc Stevens, CWI; Daniel Shumow, Microsoft Research Counter-cryptanalysis, the concept of using cryptanalytic techniques to detect cryptanalytic attacks, was introduced at CRYPTO 2013 [23] with a hash collision detection algorithm. That is, an algorithm that detects whether a given single message is part of a colliding message pair constructed using a cryptanalytic collision attack on MD5 or SHA-1. Unfortunately, the original collision detection algorithm is not a low-cost solution as it costs 15 to 224 times more than a single hash computation. In this paper we present a significant performance improvement for collision detection based on the new concept of unavoidable conditions. Unavoidable conditions are conditions that are necessary for all feasible attacks in a certain attack class. As such they can be used to quickly dismiss particular attack classes that may have been used in the construction of the message. To determine an unavoidable condition one must rule out any feasible variant attack where this condition might not be necessary, otherwise adversaries aware of counter-cryptanalysis could easily bypass this improved collision detection with a carefully chosen variant attack. Based on a conjecture solidly supported by the current state of the art, we show how we can determine such unavoidable conditions for SHA-1. We have implemented the improved SHA-1 collision detection using such unavoidable conditions and which is more than 20 times faster than without our unavoidable condition improvements. We have measured that overall our implemented SHA-1 with collision detection is only a factor 1.60 slower, on average, than SHA-1. With the demonstration of a SHA-1 collision, the algorithm presented here has been deployed by Git, GitHub, Google Drive, Gmail, Microsoft OneDrive and others, showing the effectiveness of this technique. View the full program: https://www.usenix.org/sec17/program
Views: 120 USENIX
What is asymmetric encryption?
 
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In symmetric key encryption the same key is used for both encryption and decryption. In contrast, in asymmetric key encryption a public key (known to everyone) is used for encryption and a private key (known only to the recipient) is used for decryption. Many asymmetric key encryption approaches are based on factoring as a trapdoor function, with the public key being the multiple of the two secret primes and the private key being the two secret primes. Asymmetric key encryption allows one party to encrypt a message to a second party they have never communicated with previously. Credits: Talking: Geoffrey Challen (Assistant Professor, Computer Science and Engineering, University at Buffalo). Producing: Greg Bunyea (Undergraduate, Computer Science and Engineering, University at Buffalo). Part of the https://www.internet-class.org online internet course. A blue Systems Research Group (https://blue.cse.buffalo.edu) production.
Views: 923 internet-class
Cryptography and Network Security
 
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*****Cryptography and Network Security: https://ict.iitk.ac.in/product/cryptography-and-network-security/ ***** This E & ICT Academy, IIT Kanpur "Cryptography and Network Security Tutorial” video will get an overview of modern cryptography along with an introduction to number theory. After that, you will learn about probability and information theory, classical cryptosystems, cryptanalysis of classical ciphers. Below is the list of topics covered in this session: 1. Introduction 2. Overview of Modern Cryptography 3. Introduction to Number Theory 4. Probability and Information Theory 5. Classical Cryptosystems 6. Cryptanalysis of Classical Ciphers 7. Shannons Theory 8. Shannons Theory (Contd...1) 9. Shannons Theory (Contd...2) 10. Symmetric Key Ciphers 11. Block Cipher Standards (DES) 12. Block Cipher Standards (AES) 13. Block Cipher Standards (AES) (Contd.) 14. Linear Cryptanalysis 15. Differential Cryptanalysis 16. Few other Cryptanalytic Techniques 17. Overview of S-Box Design Principles 18. Modes of Operation of Block Ciphers 19. Stream Ciphers 20. Stream Ciphers (Contd...1) 21. Stream Ciphers (Contd...2) 22. Pseudorandomness 23. Cryptographic Hash Functions 24. Cryptographic Hash Functions (Contd...1) 25. Cryptographic Hash Functions (Contd...2) Subscribe to our channel to get video updates. Hit the subscribe button above. Facebook: https://www.facebook.com/ICTAcademyIITK/ Twitter: https://twitter.com/ICTAcademyIITK Website: https://ict.iitk.ac.in/ ----------------------------------------------------------------- How it Works? 1. 24X7 Access: You can view lectures as per their own convenience. 2. Online lectures: 22 hours of video lectures are available in the course, with high-quality videos which can be viewed online. 3. Updated Quality content: The course content is latest, easy to follow, and in accordance with the current industry demands. -------------------------------------------------------------------- About the Course: Prof. Debdeep Mukhopadhyay, a faculty from the Department of Computer Science and Engineering at the IIT Kharagpur has designed this course on Cryptography and Network Security covering all the fundamental concepts of Cryptography and Network Security. In this course, you will be introduced to the areas of cryptography and cryptanalysis. You will get an overview of modern cryptography along with an introduction to number theory. After that, you will learn about probability and information theory, classical cryptosystems, cryptanalysis of classical ciphers. Then you will learn about Shannon's theory followed by symmetric key ciphers, block ciphers standards, linear and differential cryptanalysis, stream ciphers, cryptographic hash functions and a lot more. This is completely an online course, and you can access it from anywhere in the world. So, this makes it all together a complete package. During this Cryptography and Network Security Online training, you'll learn: 1. After learning the course on cryptography and network security, you will get well versed with fundamentals principles of cryptography and network security. 2. You will be able to create take advanced courses on cybersecurity and network security and effectively implement them practically. 3. Learning the principles of Cryptography and Network Security will help you to crack job interviews in this field, you will be on demand due to less availability of the Network security professionals. 4. You will be awarded a certificate from E & ICT Academy, IIT Kanpur. You can add that in your curriculum vitae. Course Objectives On completion of the Cryptography and Network Security Certification training, a learner will be able to: 1. Students: Students: All students who are pursuing any technical/professional courses, and looking for a career in Network/Cyber Security, can take this course. 2. Teachers/Faculties: All teachers/faculties who want to learn the fundamental concepts and principles of Cryptography and Network Security, and interested in delivering their knowledge and learning to their students, can take this course. The certificate will be another feather in their hat. 3. Professionals: All working professionals, who want to enhance their skills in Network/Cyber Security domain, can take this course. Who should go for this course? The demand across all industries for increased computer security is growing, and cryptography is a subcategory within the career field of information security. Cryptologists are in demand in the military forces, government agencies, technology companies, banking and financial organization s, law enforcement agencies, universities and research institutes. Depending on the profile of the organization one is involved with, the area of functioning varies. So it is worth having a go at it. Please write back to us at [email protected] or chat with us online-https://ict.iitk.ac.in/ for more information.
This Chick's Trouble: Excel Hash
 
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How can you combine unrelated Excel features to create a visualization your boss will be proud of? That's what I try to do using Excel's FREQUENCY function, Form Controls, MAX formula & 3D models. This is solution entry to Oz du Soleil's #ExcelHash competition. VOTE for your favorite here: https://tinyurl.com/y9hmvelp (voting is closed) The entire Playlist is here: https://www.youtube.com/playlist?list=PLHrPHBbDHgT0UnY1qb36YZrBwpWNJX8Lx Other ExcelMVPs in the Excel Hash challenge are: Mike Girvin - Excel Is Fun Bill Jellen - MrExcel Mynda Treacy - MyOnlineTrainingHub Jon Acampor - Excel Campus Oz du Soleil - Excel on Fire ★ Links to related videos: ★ Learn Index Match: https://youtu.be/F264FpBDX28 Charts basics: https://youtu.be/DAU0qqh_I-A ★★ My Online Excel Courses ★★ Courses ► https://courses.xelplus.com/ 🕮 Excel Resources I Recommend 🕮 https://www.xelplus.com/resources/ ✉ Subscribe & get my Excel top 10 tips and formulas e-book for free https://www.xelplus.com/free-ebook/ Music: Italian Afternoon by Twin Musicom is licensed under a Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/) Artist: http://www.twinmusicom.org/ #ExcelHash #MsExcel
Views: 19567 Leila Gharani
Inside the CPU - Computerphile
 
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Bubbles in the pipeline? Some of the basic operations at the heart of the CPU explained by Dr Steve Bagley. EXTRA BITS: https://youtu.be/t_RnwTW87_Q Why CPUs Need Caches: https://youtu.be/6JpLD3PUAZk The Perfect Code: https://youtu.be/WPoQfKQlOjg Microsoft Hololens: https://youtu.be/gp8UiYOw8Fc http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 200613 Computerphile
Turing Machine, and Breachable Cryptography
 
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Explaining how modern cryptography is built on the 1936 Turing Machine which leads to the idea of 'hardness' -- a computation that can be done, but is hard to do. This 'hardness' underlies everything in modern cryptography. Alas, hardness is not guaranteed and every one of our popular ciphers today is vulnerable to an attacker smarter than its designer. Also Turing Machines are about to give way to Quantum computers, which will do to 'modern cryptography' what modern cryptography did to 'Pre-Turing Cryptography'. Cryptography of tomorrow will be user-centric, and randomness-reliant. First in a series.
Views: 314 Gideon Samid
The Birthday Paradox
 
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3.016 Final Video project. Simple derivation of the solution to the birthday paradox with variations and ideas for further study.
Views: 2904 Ian Chesser
Hashing Lab
 
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Lab: https://dl.dropboxusercontent.com/u/40355863/csn11117_lab03.pdf
Views: 497 Bill Buchanan OBE
Our password hashing has no clothes
 
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Many of us rely on the use of salt in the belief it will make our passwords "secure" when hashed with a variant of the SHA algorithm. Unfortunately, processing power has progress to the point where even salted hashes are now near useless, particularly when using a GPU in an attempt to crack them. This video shows how salted SHA1 hashes generated by the ASP.NET membership provider can easily be broken using hashcat and an AMD Radeon 7970 GPU. This video is part of a larger blog post which includes info on alternatives here: http://www.troyhunt.com/2012/06/our-password-hashing-has-no-clothes.html
Views: 14918 Troy Hunt
Computers Without Memory - Computerphile
 
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They're called 'Finite State Automata" and occupy the centre of Chomsky's Hierarchy - Professor Brailsford explains the ultimate single purpose computer. Note: Professor Brailsford omitted the transition from the 5 state to 25 state by means of a 20p, he has amended the linked notes! Chomsky's Hierarchy: https://youtu.be/224plb3bCog $5 Computer – Raspberry Pi Zero: https://youtu.be/WR0ghM3U0M4 Why Computers Use Binary: https://youtu.be/thrx3SBEpL8 Steve Furber on ARM: https://youtu.be/1jOJl8gRPyQ CPU vs GPU: https://youtu.be/_cyVDoyI6NE Professor Brailsford's Notes: http://bit.ly/computerphile_Chomsky Professor Brailsford's t-shirt kindly supplied by Peleg Bar Sapir http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 253533 Computerphile
Ssh Authentication In Practice - Applied Cryptography
 
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This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 781 Udacity
Topic 05 A Indicator Random Variables
 
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Topic 05 A: Indicator Random Variables (as part of Probabilistic Analysis) Lecture by Dan Suthers for University of Hawaii Information and Computer Sciences course 311 on Algorithms. (Inverted course: lectures are online and problem solving in class.) Based on Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest and Clifford Stein, Introduction to Algorithms, Third Edition, The MIT Press, 2009.
Views: 9593 UHMICSAlgorithms
Different Cryptographic Controls For Ensuring CIA Explained ISO 27001 Training
 
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Thanks For Watching This Video, I Hope You Must Have Liked It. If yes then please hit the subscribe button as I will be uploading a lot of IT security related training videos on this channel and if you will be my subscriber then you my friend will be the first one who will be notified about all my new videos my friend. If you have any questions for the topic that I have discussed in this video then please feel free to comment my friend and I will be happy to respond back to your queries... Please note that - all ISO 27001 documents and standards are completely owned intellectual property & copyright of ISO. So in case if by any chance you are interested to study more about the standard that I have discussed here then please go to the official ISO website in order to purchase the standards. This channel is only created to generate awareness and best practices for Information Security in general and if by any chance you wish to implement any of the standards that I have discussed here then you have to first purchase them from official ISO website. This channel is only created to help anyone who is currently studying or planning to study about ISMS Information Security Management System ISO 27001 Implementation. I want to make my contribution in the information security community.This channel is only created to generate awareness and best practices for Information Security in general. Disclaimer: Since ISO 27001 is a very vast topic and the implementation varies for all organization's so I can't ever call myself an "expert" in this field, all the knowledge and information that I am sharing here is only based upon my past experience in information security field and may not be directly applicable within your organization as such. So please use your judgement before implementing anything based upon my suggestions. I request you not to rely on anything that I say here, I do my best to be as accurate and as complete information that I can provide you “but” only the published standards are definitive. Only the published ISO standards stand above any information that I have shared in any of my videos. Thanks, Your IT Security Friend Luv Johar Website : http://aajkatech.com/ iso 27001 explained, iso 27001 awareness trainings, iso 27001 free trainings online, Iso 27001 free tutorials, ISO 27001 training material free, lead auditor free training course, lead implementer free training course, ISMS training free, information security management system training free,
Testing Hash Functions - CS101 - Udacity
 
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Other units in this course below: Unit 1: http://www.youtube.com/playlist?list=PLF6D042E98ED5C691 Unit 2: http://www.youtube.com/playlist?list=PL6A1005157875332F Unit 3: http://www.youtube.com/playlist?list=PL62AE4EA617CF97D7 Unit 4: http://www.youtube.com/playlist?list=PL886F98D98288A232 Unit 5: http://www.youtube.com/playlist?list=PLBA8DEB5640ECBBDD Unit 6: http://www.youtube.com/playlist?list=PL6B5C5EC17F3404D6 Unit 7: http://www.youtube.com/playlist?list=PL6511E7098EC577BE Q&A: http://www.youtube.com/playlist?list=PLDA5F9F71AFF4B69E To gain access to interactive quizzes, homework, programming assignments and a helpful community, join the class at http://www.udacity.com
Views: 878 Udacity
What is RANDOMIZATION FUNCTION? What does RANDOMIZATION FUNCTION mean?
 
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What is RANDOMIZATION FUNCTION? What does RANDOMIZATION FUNCTION mean? RANDOMIZATION FUNCTION meaning - RANDOMIZATION FUNCTION definition - RANDOMIZATION FUNCTION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In computer science, a randomization function or randomizing function is an algorithm or procedure that implements a randomly chosen function between two specific sets, suitable for use in a randomized algorithm. Randomizing functions are related to random number generators and hash functions, but have somewhat different requirements and uses, and often need specific algorithms. Randomizing functions are used to turn algorithms that have good expected performance for random inputs, into algorithms that have the same performance for any input. For example, consider a sorting algorithm like quicksort, which has small expected running time when the input items are presented in random order, but is very slow when they are presented in certain unfavorable orders. A randomizing function from the integers 1 to n to the integers 1 to n can be used to rerrange the n input items in "random" order, before calling that algorithm. This modified (randomized) algorithm will have small expected running time, whatever the input order. In theory, randomization functions are assumed to be truly random, and yield an unpredictably different function every time the algorithm is executed. The randomization technique would not work if, at every execution of the algorithm, the randomization function always performed the same mapping, or a mapping entirely determined by some externally observable parameter (such as the program's startup time). With such a "pseudo-randomization" function, one could in principle construct a sequence of calls such that the function would always yield a "bad" case for the underlying deterministic algorithm. For that sequence of calls, the average cost would be closer to the worst-case cost, rather than the average cost for random inputs. In practice, however, the main concern is that some "bad" cases for the deterministic algorithm may occur in practice much more often than it would be predicted by chance. For example, in a naive variant of quicksort, the worst case is when the input items are already sorted — which is a very common occurrence in many applications. For such algorithms, even a fixed pseudo-random permutation may be good enough. Even though the resulting "pseudo-randomized" algorithm would still have as many "bad" cases as the original, they will be certain peculiar orders that would be quite unlikely to arise in real applications. So, in practice one often uses randomization functions that are derived from pseudo-random number generators, preferably seeded with external "random" data such as the program's startup time. The uniformity requirements for a randomizing function are usually much weaker than those of hash functions and pseudo-random generators. The minimum requirement is that it maps any input of the deterministic algorithm into a "good" input with a sufficiently high probability. (However, analysis is usually simpler if the randomizing function implements each possible mapping with uniform probability.)
Views: 143 The Audiopedia
What is ENCRYPTED KEY EXCHANGE? What does ENCRYPTED KEY EXCHANGE mean?
 
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What is ENCRYPTED KEY EXCHANGE? What does ENCRYPTED KEY EXCHANGE mean? ENCRYPTED KEY EXCHANGE meaning - ENCRYPTED KEY EXCHANGE definition - ENCRYPTED KEY EXCHANGE explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ Encrypted Key Exchange (also known as EKE) is a family of password-authenticated key agreement methods described by Steven M. Bellovin and Michael Merritt. Although several of the forms of EKE in this paper were later found to be flawed , the surviving, refined, and enhanced forms of EKE effectively make this the first method to amplify a shared password into a shared key, where the shared key may subsequently be used to provide a zero-knowledge password proof or other functions. In the most general form of EKE, at least one party encrypts an ephemeral (one-time) public key using a password, and sends it to a second party, who decrypts it and uses it to negotiate a shared key with the first party. A second paper describes Augmented-EKE, and introduced the concept of augmented password-authenticated key agreement for client/server scenarios. Augmented methods have the added goal of ensuring that password verification data stolen from a server cannot be used by an attacker to masquerade as the client, unless the attacker first determines the password (e.g. by performing a brute force attack on the stolen data). A version of EKE based on Diffie-Hellman, known as DH-EKE, has survived attack and has led to improved variations, such as the PAK family of methods in IEEE P1363.2. With the US patent on EKE expiring in late 2011, an EAP authentication method using EKE was published as an IETF RFC. The EAP method uses the Diffie-Hellman variant of EKE.
Views: 224 The Audiopedia
Just How do Macs and PCs Differ? - Computerphile
 
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Following on from our contentious 'Mac or PC' film, we asked Professor Tom Rodden just what the actual difference is between Mac and PC. (by PC we are referring to machines running Windows or a variant of Linux) Floating Point Numbers: http://youtu.be/PZRI1IfStY0 Mac or PC? : http://youtu.be/A_Zptl34hbo Heartbleed, Running the Code: http://youtu.be/1dOCHwf8zVQ http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. See the full list of Brady's video projects at: http://bit.ly/bradychannels
Views: 871837 Computerphile
The Mathematics of Diffie-Hellman Key Exchange | Infinite Series
 
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Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/donateinfi Symmetric keys are essential to encrypting messages. How can two people share the same key without someone else getting a hold of it? Upfront asymmetric encryption is one way, but another is Diffie-Hellman key exchange. This is part 3 in our Cryptography 101 series. Check out the playlist here for parts 1 & 2: https://www.youtube.com/watch?v=NOs34_-eREk&list=PLa6IE8XPP_gmVt-Q4ldHi56mYsBuOg2Qw Tweet at us! @pbsinfinite Facebook: facebook.com/pbsinfinite series Email us! pbsinfiniteseries [at] gmail [dot] com Previous Episode Topology vs. “a” Topology https://www.youtube.com/watch?v=tdOaMOcxY7U&t=13s Symmetric single-key encryption schemes have become the workhorses of secure communication for a good reason. They’re fast and practically bulletproof… once two parties like Alice and Bob have a single shared key in hand. And that’s the challenge -- they can’t use symmetric key encryption to share the original symmetric key, so how do they get started? Written and Hosted by Gabe Perez-Giz Produced by Rusty Ward Graphics by Ray Lux Assistant Editing and Sound Design by Mike Petrow and Meah Denee Barrington Made by Kornhaber Brown (www.kornhaberbrown.com) Thanks to Matthew O'Connor, Yana Chernobilsky, and John Hoffman who are supporting us on Patreon at the Identity level! And thanks to Nicholas Rose, Jason Hise, Thomas Scheer, Marting Sergio H. Faester, CSS, and Mauricio Pacheco who are supporting us at the Lemma level!
Views: 51381 PBS Infinite Series
CERIAS Symposium 2017 - TechTalk - Jeremiah M. Blocki
 
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Jeremiah M. Blocki Assistant Professor, Computer Science Purdue University “Memory Hard Functions and Password Hashings” In the last few years breaches at organizations like Yahoo!, Dropbox, Lastpass, AshleyMadison and Adult FriendFinder have exposed over a billion user passwords to offline attacks. Password hashing algorithms are a critical last line of defense against an offline attacker who has stolen password hash values from an authentication server. A attacker who has stolen a user’s password hash value can attempt to crack each user’s password offline by comparing the hashes of likely password guesses with the stolen hash value. A good password hashing algorithm should have the property that it is feasible to compute the function quickly (e.g., 0.5 seconds) on a personal computer, but it should be economically infeasible for an offline attacker to check millions (or billions) of password guesses. Memory hard functions (MHFs), first explicitly introduced by Percival, are a promising key-stretching tool for password hashing because the cost of storing/retrieving items from memory is relatively constant across different computer architectures. Thus, in contrast to standard cryptographic hash functions (e.g., SHA256) the cost of computing an MHF cannot be significantly reduced by developing customized hardware (ASICs). More specifically, we want to ensure that any circuit evaluating multiple instances of the MHF has high amortized AT-complexity --- Area X Time/#instances. Data-Independent Memory Hard Functions (iMHFs) are an important variant of MHFs due to their greater resistance to side-channel attacks. An iMHF can be specified by a directed acyclic G specifying data-dependencies during computation. Due to the recently completed Password Hashing Competition we have many candidate iMHFs, but many of these iMHFs had not been analyzed until recently. This talk will summarize recent results demonstrating that a combinatorial property called depth-robustness fully characterizes iMHFs with high amortized-AT complexity. We will also show that Argon2i, the winner of the password hashing competition, is defined using a directed acyclic graph G that is not depth-robust. The resulting attacks are practical for realistic settings of the Argon2i parameters. We will also discuss recent progress towards the development of a practical iMHF with provably high AT-complexity. https://www.cerias.purdue.edu/site/symposium2017 Disclaimer: https://www.cerias.purdue.edu/news_and_events/events/security_seminar/#disclaimer
Views: 63 ceriaspurdue
Dual-Server Public-Key Encryption With Keyword Search for Secure Cloud Storage
 
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Dual-Server Public-Key Encryption With Keyword Search for Secure Cloud Storage To get this project in ONLINE or through TRAINING Sessions, Contact: JP INFOTECH, Old No.31, New No.86, 1st Floor, 1st Avenue, Ashok Pillar, Chennai -83.Landmark: Next to Kotak Mahendra Bank. Pondicherry Office: JP INFOTECH, #45, Kamaraj Salai,Thattanchavady, Puducherry -9.Landmark: Next to VVP Nagar Arch. Mobile: (0) 9952649690, Email: [email protected], web: http://www.jpinfotech.org, Blog: http://www.jpinfotech.blogspot.com Searchable encryption is of increasing interest for protecting the data privacy in secure searchable cloud storage. In this paper, we investigate the security of a well-known cryptographic primitive, namely, public key encryption with keyword search (PEKS) which is very useful in many applications of cloud storage. Unfortunately, it has been shown that the traditional PEKS framework suffers from an inherent insecurity called inside keyword guessing attack (KGA) launched by the malicious server. To address this security vulnerability, we propose a new PEKS framework named dual-server PEKS (DS-PEKS). As another main contribution, we define a new variant of the smooth projective hash functions (SPHFs) referred to as linear and homomorphic SPHF (LH-SPHF). We then show a generic construction of secure DS-PEKS from LH-SPHF. To illustrate the feasibility of our new framework, we provide an efficient instantiation of the general framework from a Decision Diffie–Hellman-based LH-SPHF and show that it can achieve the strong security against inside the KGA.
Views: 2433 JPINFOTECH PROJECTS
Clustering Algorithms for Perceptual Image Hashing
 
51:07
A perceptual image hash function maps an image to a short binary string based on an image's appearance to the human eye. Perceptual hashing is useful in image databases, watermarking, and content authentication in adversarial scenarios. In this talk, we decouple image hashing into feature extraction (intermediate hash) followed by data clustering (final hash). We prove that the decision version of our clustering problem is NP complete. Then, for any perceptually significant feature extractor, we present a polynomial-time clustering algorithm based on a greedy heuristic, which automatically determines the final hash length needed to satisfy a specified distortion. Based on the proposed algorithm, we develop two variations to facilitate perceptual robustness vs. fragility trade-offs. We validate the perceptual significance of our hash by testing under Stirmark attacks. Finally, we develop randomized clustering algorithms for the purposes of secure image hashing. We demonstrate the hardness of generating malicious inputs by means of experimental results.
Views: 631 Microsoft Research
14. SSL and HTTPS
 
01:18:18
MIT 6.858 Computer Systems Security, Fall 2014 View the complete course: http://ocw.mit.edu/6-858F14 Instructor: Nickolai Zeldovich In this lecture, Professor Zeldovich discusses how to cryptographically protect network communications, as well as how to integrate cryptographic protection of network traffic into the web security model. License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
Views: 72215 MIT OpenCourseWare
Secure Web Browsing - Computerphile
 
12:20
Websites & https what difference does the "s" make anyway? - Dr Richard Mortier of the University of Cambridge Computer Laboratory explains. Follow the Cookie Trail: https://youtu.be/LHSSY8QNvew Man in the Middle / Superfish: https://youtu.be/-enHfpHMBo4 Botnets: COMING SOON Object Oriented Programming: https://youtu.be/KyTUN6_Z9TM 3D Rock Art Scanner: https://youtu.be/Ahdnkj77rAY Mixed Reality Continuum: https://youtu.be/V4qxfFPgqdc http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 126904 Computerphile
Properties Of Modes Solution - Applied Cryptography
 
02:14
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 955 Udacity
How Bitcoin Works Under the Hood
 
22:25
A somewhat technical explanation of how Bitcoin works. Want more? Check out my new in-depth course on the latest in Bitcoin, Blockchain, and a survey of the most exciting projects coming out (Ethereum, etc): https://app.pluralsight.com/library/courses/bitcoin-decentralized-technology Lots of demos on how to buy, send, store (hardware, paper wallet). how to use javascript to send bitcoin. How to create Ethereum Smart Contract, much more. Shorter 5 min introduction: https://www.youtube.com/watch?v=t5JGQXCTe3c Written version: http://www.imponderablethings.com/2013/07/how-bitcoin-works-under-hood.html My Bitcoin address: 13v8NB9ScRa21JDi86GmnZ5d8Z4CjhZMEd Arabic translation by Ahmad Alloush Spanish caption translation by Borja Rodrigo, [email protected], DFJWgXdBCoQqo4noF4fyVhVp8R6V62XdJx Russian caption translation by Alexandra Miklyukova Italian voice over: http://youtu.be/1aEf3qr7UdE Italian captions translated by Simone Falcini, 1H5KdCnBooxfqpXtyQBBAKKRU7MkCZCVCe
Views: 2656754 CuriousInventor
On the Preimage Resistance of SHA-1
 
35:33
We show that preimages of SHA-1 can be computed at the cost of 2^159.3 compression function computations. For variants with a reduced number of steps we obtain significantly faster attacks than previously known. The best previous attack was on 48 (of 80) steps with a complexity of 2^159.3. Our attack on this variant has complexity 2^152.1. The new results heavily rely on the linear message expansion and the low diffusion of the step transformation. The techniques in this paper apply to any hash function with linear message expansion. In the talk we will provide a general introduction to meet-in-the-middle preimage attacks on hash functions.
Views: 290 Microsoft Research
Login and Registration page in PHP and MySQL - Part 5 : Add Security by MD5 Encryption on Passwords
 
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In this video tutorial we will add md5 hash algorithm to perform encryption of passwords which are stored in the MySQL database. We will use the inbuilt PHP function md5() to encrypt the password string and then store that string in the Database. This video is a enchancement of part 1 and part 2 of the login and registration tutorial playlist so if you are new, make sure you watch those videos first. Download the Project source files here (for Non Encrypted) : https://www.mediafire.com/file/ax1wt4j3d7htl0t/LoginPage.rar Download the Project source files here (for Encrypted) : http://www.mediafire.com/file/dj77neaa1dr46g3/SampleLoginPageEncryption.rar Simple Snippets Official Website - https://simplesnippets.tech/ Simple Snippets on Facebook- https://www.facebook.com/simplesnippets/ Simple Snippets on Instagram- https://www.instagram.com/simplesnippets/ Simple Snippets email ID- [email protected] For Classroom Coaching in Mumbai for Programming & other IT/CS Subjects Checkout UpSkill Infotech - https://upskill.tech/ UpSkill is an Ed-Tech Company / Coaching Centre for Information Technology / Computer Science oriented courses and offer coacing for various Degree courses like BSc.IT, BSc.CS, BCA, MSc.IT, MSc.CS, MCA etc. Contact via email /call / FB /Whatsapp for more info email - [email protected] We also Provide Certification courses like - Android Development Web Development Java Developer Course .NET Developer Course Check us out on Social media platforms like Facebook, Instagram, Google etc Facebook page - https://www.facebook.com/upskillinfotech/ Insta page - https://www.instagram.com/upskill_infotech/ Google Maps - https://goo.gl/maps/vjNtZazLzW82
Views: 6881 Simple Snippets
cityhash
 
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Introduction to CityHash https://hash.onlinetoolsland.com/cityhash/ The CityHash is a family of hash functions for strings, there are currently 2 type of CityHash CityHash64 and CityHash128. They can hash 64- and 128-bit hash codes, respectively. The cityhash is quite good for hash tables. but not the aren’t suitable for cryptography, The CityHash is invent and published by google. When the enginners at google tried to optimize for CPUs that are common in Google’s datacenters, they find out most PCs and laptops have the relevant features as well. The important ones are 64-bit registers, instruction-level parallelism, and fast unaligned memory accesses. Google thinks CityHash64 and CityHash128 are exciting new method to to solve a classic problem. Under real-life conditions they expect CityHash64 to outperform previous work by at least 30% in speed, and perhaps as much as a factor of two. Also, as far as we know, these functions’ statistical properties are sound. Please don’t hesitate to try this fast new code! Introduction to the CityHash The city hash is a a family of hash functions for strings.The cityhash is a hash functions for strings. ,but the cityhash are not suitable for cryptography. The CityHash32() returns a 32-bit hash. The CityHash64() and similar return a 64-bit hash. The CityHash128() and similar return a 128-bit hash and are used for strings of at least a few hundred bytes. The cityhash 128 almost always faster than CityHash64() on enough long strings. Depending on your compiler and hardware,and at the same time the cityhash 128 It's slower than necessary on shorter strings There are also CityHashCrc128() amd CityHashCrc256(),which return 128-bit hash. And 256-bit hash. All the hash function in the CityHash family are designed upon the work by Bob Jenkins Austin Appleby and others.such as Murmur3a The per Performance of CityHash famlily The Performance of CityHash64 and its many variants on both short and long are both interesting The cityhash is designed to be a fast algorithm ,under certain conditions , it runs quite fast On a sole core of a 2.67GHz Intel Xeon X5550, the CityHashCrc256 can run at max of 5 to 5.5 bytes/cycle. The other CityHashCrc hashes are wrappers around CityHashCrc256 and have similar performance on long strings. The CityHash128 peaks at about 4.3 bytes/cycle. Compare with other hashes There are some hash just like the cityhash , include SpookyHash by Bob Jenkins And Murmur hash. The performance on long strings For operate on long strings, pookyHash, is just A little slower than CityHash128 on Intel x86-64 CPUs, but more faster on AMD x86-64 CPUs. For operating on hashing long strings on AMD CPUs and/or CPUs without the CRC instruction, SpookyHash may be just as good or better than any of the CityHash variants. The performance on on short strings: 64-bit CPUs for operating on short strings, CityHash64 is faster than CityHash128, and probably faster than all the aforementioned functions, depending on the mix of string lengths. Hash Results CityHash64 v1.0.3 7ns for 1 byte, or 6ns for 8 bytes, or 9ns for 64 bytes Murmur2 (64-bit) 6ns for 1 byte, or 6ns for 8 bytes, or 15ns for 64 bytes Murmur3F 14ns for 1 byte, or 15ns for 8 bytes, or 23ns for 64 bytes The performance on 32-bit CPUs The CityHash32 is the newest variant of CityHash. It is designed for 32-bit hardware in general but has been mostly tested on x86. We don't know of anything faster that has comparable quality. The speed rankings in our testing: CityHash32 Murmur3f Murmur3a (for long strings), and CityHash32 Murmur3a Murmur3f (for short strings). https://hash.onlinetoolsland.com/cityhash/
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Concrete Problems in AI Safety (Paper) - Computerphile
 
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AI Safety isn't just Rob Miles' hobby horse, he shows us a published paper from some of the field's leading minds. More from Rob Miles on his channel: http://bit.ly/Rob_Miles_YouTube Apologies for the focus issues throughout this video, they were due to a camera fault. :( Thanks as ever to Nottingham Hackspace (at least the camera fault allows you to read some of their book titles) Concrete Problems in AI Safety paper: https://arxiv.org/pdf/1606.06565.pdf AI 'Stop Button' Problem: https://youtu.be/3TYT1QfdfsM Onion Routing: https://youtu.be/QRYzre4bf7I http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com
Views: 155443 Computerphile
BEST CRYPTO CURRENCY DASH MINER ANTMINER D3 X11 15GH/s
 
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Antminer D3: Best Dash Miner Specifications of the Antminer D3 are as follows: a) Hash rate: 15 GH/s (Variation of ±5% is expected) b) Power consumption: 1200W (at the wall, with Bitmain’s APW3 PSU, 93% efficiency, 25°C ambient temp). c) Dimensions of the miner: 320*130*190mm d) Hashing algorithm: X11 Referral links: Mining https://www.genesis-mining.com/ Genesis Mining: Use my code "" mZPezX"" to get 3% off of genesis mining and I will use your code next time I upgrade https://minergate.com/a/a8b56b14a0b40... Miner Gate: Mine the most profitable coin on your desktop with the click of a button Trading https://www.cryptopia.co.nz/Register?... Cryptopia: Trade a large amount of coins easily.
Views: 1680 Crypto Crab