Who generates the nonce? What makes it random? How is nonce-guessing important to the competitive process of mining? What happens if the hashing algorithm (SHA-256) was compromised? Is quantum computing a threat? More on nonces and the mining process: https://github.com/bitcoinbook/bitcoinbook/blob/8ae3c056fb257111bda8883d9d204e8476f9870c/ch09.asciidoc More about the SHA-1 collision: https://security.googleblog.com/2017/02/announcing-first-sha1-collision.html More about SHA-1 and Bitcoin: https://bitcoin.stackexchange.com/questions/75135/is-sha-1-used-in-bitcoin CORRECTION: At 5:53, I described what a collision was. However, the definition I outlined was actually for a pre-image attack, which is distinct from collision attacks. The subtitles have been edited to include the correction. https://en.wikipedia.org/wiki/Preimage_attack These questions are from the MOOC 7.2 and 9.2, which took place on February 26th 2017 and February 23rd 2018 respectively. Andreas is a teaching fellow with the University of Nicosia. The first course in their Master of Science in Digital Currency degree, DFIN-511: Introduction to Digital Currencies, is offered for free as an open enrollment MOOC course to anyone interested in learning about the fundamental principles. If you want early-access to talks and a chance to participate in the monthly live Q&As with Andreas, become a patron: https://www.patreon.com/aantonop RELATED: Consensus Algorithms, Blockchain Technology, and Bitcoin - https://youtu.be/fw3WkySh_Ho Advanced Bitcoin Scripting Part 1: Transactions and Multisig - https://youtu.be/8FeAXjkmDcQ Advanced Bitcoin Scripting Part 2: SegWit, Consensus, and Trustware - https://youtu.be/pQbeBduVQ4I What is Consensus: Rules without Rulers - https://youtu.be/2tqo7PX5Pyc Forkology: A Study of Forks for Newbies - https://youtu.be/rpeceXY1QBM Bitcoin: Where the Laws of Mathematics Prevail - https://youtu.be/HaJ1hvon0E0 Software distribution security - https://youtu.be/_V0vqy046YM What is mining? - https://youtu.be/t4p4iMqmxbQ The mining process - https://youtu.be/L4Xtau0YMJw Miners, pools, and consensus - https://youtu.be/JHz7LM4ncLw Cryptographic primitives - https://youtu.be/RIckQ6RBt5E The rules of Bitcoin (part 1) - https://youtu.be/VnQu4uylfOs The rules of Bitcoin (part 2) - https://youtu.be/vtIp0GP4w1E Rules versus rulers - https://youtu.be/9EEluhC9SxE The value of proof-of-work - https://youtu.be/ZDGliHwstM8 Migrating to post-quantum cryptography - https://youtu.be/dkXKpMku5QY Could a state-sponsored 51% attack work? - https://youtu.be/KUd8ZGgm6Qo Honest nodes and consensus - https://youtu.be/KAhY2ymI-tg Spam transactions and Child Pays For Parent (CPFP) - https://youtu.be/t3c0E4fkSNs Is Bitcoin a democracy? - https://youtu.be/TC3Hq76UT5g Decentralized power, leaderless governance - https://youtu.be/E5VbDlQTPzU Scaling, trust, and trade-offs - https://youtu.be/vCxmHwqyJWU What is the role of nodes? - https://youtu.be/fNk7nYxTOyQ Why running a node is important - https://youtu.be/oX0Yrv-6jVs Lightning, full nodes, and miners - https://youtu.be/dlJG4OHdJzs Running nodes and payment channels - https://youtu.be/ndcfBfE_yoY What happens during a fork? - https://youtu.be/XBk8hBJ1xVo SegWit adoption - https://youtu.be/KCsTVTRk6I4 Spam transactions and Child Pays For Parent (CPFP) - https://youtu.be/t3c0E4fkSNs Energy consumption - https://youtu.be/2T0OUIW89II Solar energy and mining in space - https://youtu.be/cusakcpa8AM Bitmain and ASICBoost allegations - https://youtu.be/t6jJDD2Aj8k Andreas M. Antonopoulos is a technologist and serial entrepreneur who has become one of the most well-known and respected figures in bitcoin. Follow on Twitter: @aantonop https://twitter.com/aantonop Website: https://antonopoulos.com/ He is the author of two books: “Mastering Bitcoin,” published by O’Reilly Media and considered the best technical guide to bitcoin; “The Internet of Money,” a book about why bitcoin matters. THE INTERNET OF MONEY, v1: https://www.amazon.co.uk/Internet-Money-collection-Andreas-Antonopoulos/dp/1537000454/ref=asap_bc?ie=UTF8 [NEW] THE INTERNET OF MONEY, v2: https://www.amazon.com/Internet-Money-Andreas-M-Antonopoulos/dp/194791006X/ref=asap_bc?ie=UTF8 MASTERING BITCOIN: https://www.amazon.co.uk/Mastering-Bitcoin-Unlocking-Digital-Cryptocurrencies/dp/1449374042 [NEW] MASTERING BITCOIN, 2nd Edition: https://www.amazon.com/Mastering-Bitcoin-Programming-Open-Blockchain/dp/1491954388 Subscribe to the channel to learn more about Bitcoin & open blockchains! Music: "Unbounded" by Orfan (https://www.facebook.com/Orfan/) Outro Graphics: Phneep (http://www.phneep.com/) Outro Art: Rock Barcellos (http://www.rockincomics.com.br/)
Views: 10703 aantonop
Views: 2656205 CuriousInventor
BLOCKCHAIN: Blockchain Beginner's Explained - Blockchain Review ★ CONTACTS ➤ [email protected] Just what is Blockchain Blockchain, the underlying modern technology that powers bitcoin, is just one of the buzzwords of the previous year. Almost everybody is speaking about blockchain, and also forever factor. Dispersed journals, the regard to art for blockchain's underlying modern technology, supply an amazing brand-new means to negotiate organisation without a main authority. Below's a nontechnical, streamlined summary of the part. Blockchain specified A blockchain, or dispersed journal, is a constantly expanding checklist (electronic documents) of encrypted purchases called "blocks" that are dispersed (duplicated) to a peer-to-peer (P2P) network of computer systems. Blocks As defined over, a blockchain is an unalterable, consecutive chain of documents referred to as blocks. A block could consist of any type of sort of information, such as one-of-a-kind electronic identifiers of physical items. Blocks are "chained" with each other utilizing hashes. A hash is a feature that takes an input worth and also from that input develops an outcome worth deterministic of the input worth. Along with individual information, each block will certainly include an index, a timestamp, a listing of purchases, an evidence as well as the hash of the previous block. The hash The hash plays an important duty. Since each brand-new block will certainly consist of a hash of the previous block, blockchains are unalterable. If a cyberpunk were to corrupt an earlier block in the blockchain, all succeeding blocks would certainly have inaccurate hashes. Encrypted purchases Encrypted purchases (making use of traditional public/private essential cryptography) are likewise vital to blockchain's worth. The customer's "public secret" is kept in a block as well as comes to be an "address" on the blockchain. Documents such as cryptocurrencies or various other electronic properties are taped as coming from a certain block. An equivalent "exclusive trick" is called for to access the linked electronic properties. Maintaining your exclusive crucial personal is so vital that to secure their electronic properties from cyberpunks, many individuals do not maintain electronic duplicates of their personal secrets. They compose the number on a paper as well as maintain the paper in a safe area (like a wall surface secure). Evidence of Job (PoW). When a blockchain is instantiated, an Evidence of Job formula (PoW) is made use of to develop or "mine" brand-new blocks. The existing bitcoin mining method offers a fine example of PoW use. This strategy is explained in Wikipedia as complies with: "A bitcoin miner runs a computer system program that gathers unofficial purchases from coin dealerships in the network. With various other information these could create a block as well as gain a settlement to the miner, however a block is approved by the network just when the miner finds by experimentation a 'nonce' number that when consisted of in the block generates a hash with an enough variety of leading absolutely no little bits to fulfill the network's problem target. Blocks approved from miners develop the bitcoin blockchain that is an expanding journal of every bitcoin purchase because the coin's initial development.". Public or exclusive. There are 2 basic sorts of blockchain networks: confidential networks, where each customer has a duplicate of the whole blockchain as well as assists procedure and also verify purchases; as well as permission-based (non-anonymous) networks, where consent is called for to have a duplicate of the blockchain as well as in order to help procedure as well as verify deals. Besides cryptocurrencies, just what can you make with blockchain? Blockchain provides a means to validate purchases without the requirement for a main authority. This implies you could develop clever agreements making use of dispersed journals. For instance, a proprietor may place an IoT door lock on your rental house. The door lock could examine the blockchain to see if your lease is paid. If it isn't really, the door lock (that is, the wise agreement) would certainly not allow you right into the home. In an extra complicated situation, a company can release its very own bonds and also purchasers can keep track of settlements by means of a dispersed journal. A much more complicated usage situation would certainly be the production of self-enforcing profession arrangements. The listing of usages for blockchain is virtually limitless. From title searches to shipment confirmation, dispersed journals provide a totally brand-new, safe and secure means to do company. Your essential inquiry is: "For this job, is a blockchain a far better selection compared to a well-crafted, safe data source?" Afterwards, you get on your method!
Views: 10459 ICO REVIEW
This video explains some of the academic research performed in the ACM CCS 2017 paper "Key Reinstallation Attacks: Forcing Nonce Reuse in WPA2". It's not a guide or tutorial on how to hack people. Instead, the video was made to make people aware of potential risks, and to motivate everyone to update their smartphone and laptop. By updating your devices you (normally) avoid the risks mentioned in the video! For additional information visit https://www.krackattacks.com Note that devices different from Android and Linux are less affected by the attack. That's because only Android and Linux (re)install an all-zero encryption key.
Views: 1120612 Mathy Vanhoef
More from Entertainment Tonight: http://bit.ly/1xTQtvw Judge Judy's handled some pretty ridiculous defendants -- but this one takes the cake!
Views: 5442769 Entertainment Tonight
Various cryptographer and Quantum experts from around the world warn that a Quantum Computer attack is imminent. They recommend all sectors implement security to avoid being compromised. __ Thank You For Watching This Video! 🎞 SUBSCRIBE to our channel for daily Breaking News in Crypto here -- https://www.youtube.com/channel/UCuDgA_9Qxl4DONETl-UfM3Q __ 🔹 Welcome to BloxLive.TV, the world's first crypto and blockchain news network streaming around the clock. We feature breaking news, market analysis and event coverage in this dynamic and revolutionary finance and technology marketplace. __ 🔹The BloxLive.TV consists of journalists, techies, finance experts, thought leaders and business professionals with the shared vision to provide the global crypto and blockchain community with resources previously only available in traditional finance and tech media. __ BloxLive.TV begins where mainstream media ends. We broadcast this Revolution Livestream! __ 💻FOLLOW US HERE: ►Twitter: https://twitter.com/bloxlivetv ►Instagram: https://www.instagram.com/bloxlive/ ►Facebook: https://www.facebook.com/bloxlive/ ►LinkedIn: https://www.linkedin.com/company/bloxlive/ ►Visit our Official Website: https://bloxlive.tv
Views: 53 Bloxlive
In this session, Preethi Kasireddy explains how Proof of Work actually works in decentralized systems, gossip protocol, attacks that are possible due to selfish mining, SHA-256, and more. Join the TruStory Expert Community today https://boards.greenhouse.io/trustory/jobs/4128579002 Study Session Outline Consensus [1:00] Gossip Protocol [2:29] How the Proof of Work system works [4:54] What happens when multiple miners broadcast a valid solution at the same time? [12:31] Calculating time in a decentralized system as it relates to Proof of Work [17:19] Bitcoins difficulty adjustment algorithm [21:38] Selfish mining attacks [26:33] Chia Network (proof of space and time consensus algorithm) [33:55] Example of a 51% attack [43:40] Review from Bitcoin White Paper on how transactions work [51:59] Merkle root [53:36] _____________________________________________________________________ If interested, you can view TruStory’s study session on Bitcoin’s White Paper here: https://www.youtube.com/watch?v=QqD7IT5EcpM&t=380s Articles and writings mentioned during study session: Majority is not Enough: Bitcoin Mining is Vulnerable (by Ittay Eyal and Emin Gun Sirer): https://www.cs.cornell.edu/~ie53/publications/btcProcFC.pdf Blockchain Proof-of-Work Is a Decentralized Clock: https://grisha.org/blog/2018/01/23/explaining-proof-of-work/ A New Approach to Thwarting “Selfish” Bitcoin Miners: https://bitcoinmagazine.com/articles/new-approach-thwarting-selfish-bitcoin-miners/ Vertcoin (VTC) was successfully 51% attacked: https://medium.com/coinmonks/vertcoin-vtc-is-currently-being-51-attacked-53ab633c08a4 Connect with us: If you have questions, post em to our Discourse: https://discourse.trustory.io/ If you find false claims, @ us on Twitter: https://twitter.com/isTrustory If you wanna get updates on TruStory, check out our website: https://www.trustory.io/
Views: 94 Experts @ TruStory
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 gives a brief overview of the class, summarizing class organization and the concept of threat models. License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
Views: 381034 MIT OpenCourseWare
Ethereum is an open-source, public, blockchain-based distributed computing platform and operating system featuring smart contract functionality. It supports a modified version of Nakamoto consensus via transaction based state transitions. In popular discourse, the term Ethereum is often used interchangeably with Ether to refer to the cryptocurrency that is generated on the Ethereum platform. Ether is a cryptocurrency whose blockchain is generated by the Ethereum platform. Ether can be transferred between accounts and used to compensate participant mining nodes for computations performed. Ethereum provides a decentralized Turing-complete virtual machine, the Ethereum Virtual Machine , which can execute scripts using an international network of public nodes. "Gas", an internal transaction pricing mechanism, is used to mitigate spam and allocate resources on the network. Ethereum was proposed in late 2013 by Vitalik Buterin, a cryptocurrency researcher and programmer. Development was f... http://www.wikividi.com ____________________________________ Shortcuts to chapters: 00:01:52 Etymology 00:02:19 History 00:03:33 Enterprise Ethereum Alliance (EEA) 00:04:28 Milestones 00:06:01 The DAO event 00:07:02 Ether 00:07:38 Characteristics 00:09:07 Addresses 00:10:14 Supply 00:10:46 Markets and stores 00:11:03 Virtual Machine ____________________________________ Copyright WikiVidi. Licensed under Creative Commons. Wikipedia link: https://en.wikipedia.org/wiki/Ethereum
Views: 38 WikiVidi Documentaries
Neste vídeo, Vitalik Buterin, criador do Ethereum, explica o protocolo do Blockchain da rede Ethereum.
Views: 40 Foxbit Educação