Search results “Number of symmetric boolean functions in cryptography”
Xor Function - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 17933 Udacity
RSA Algorithm with solved example using extended euclidean algorithm | CSS series #7
#rsa #deffiehellman #cryptographylectures #lastmomenttuitions Take the Full Course of Cryptography and Network Security What we Provide 1) 20 Videos (Index is given down) + More Update will be Coming Before final exams 2)Hand made Notes with problems for your to practice 3)Strategy to Score Good Marks in Cryptography and Network Scurity To buy the course click https://goo.gl/mpbaK3 if you have any query email us at [email protected] Sample Notes : https://goo.gl/Ze1FpX or Fill the form we will contact you https://goo.gl/forms/2SO5NAhqFnjOiWvi2 Cryptography and System Security Index Lecture 1 Introduction to Cryptography and Security System Lecture 2 Security Goals and Mechanism Lecture 3 Symmetric Cipher Lecture 4 Substitution Cipher Lecture 5 Transposition Cipher Lecture 6 Stream and Block Cipher Lecture 7 Mono Alphabetic Cipher Lecture 8 Poly Alphabetic Cipher Lecture 9 Diffie Hellman Lecture 10 RSA Algorithm with Solved Example Lecture 11 IDEA Algorithm Full Working Lecture 12 SHA-1 Algorithm Full Working Lecture 13 Blowfish Algorithm Full working Lecture 14 DES Algorithm Full Working Lecture 15 Confusion and Diffusion Lecture 16 AES Algorithm Full working Lecture 17 Kerberos Lecture 18 Malicious Software ( Virus and worms ) Lecture 19 DOS and DDOS Attack Lecture 20 Digital Signature Full working Explained More videos Coming Soon.
Views: 280477 Last moment tuitions
Chapter 3, part 1: Symmetric Key Crypto --- stream ciphers, A5/1, shift registers
Information Security: Principles and Practice, 2nd edition, by Mark Stamp Chapter 3: Symmetric Key Crypto Sections 3.1-3.2.1 stream ciphers, A5/1, shift registers Class Lecture, 2011
Views: 27953 Mark Stamp
Logic Gate - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 1082 Udacity
Symmetric Key and Public Key Encryption
Modern day encryption is performed in two different ways. Check out http://YouTube.com/ITFreeTraining or http://itfreetraining.com for more of our always free training videos. Using the same key or using a pair of keys called the public and private keys. This video looks at how these systems work and how they can be used together to perform encryption. Download the PDF handout http://itfreetraining.com/Handouts/Ce... Encryption Types Encryption is the process of scrambling data so it cannot be read without a decryption key. Encryption prevents data being read by a 3rd party if it is intercepted by a 3rd party. The two encryption methods that are used today are symmetric and public key encryption. Symmetric Key Symmetric key encryption uses the same key to encrypt data as decrypt data. This is generally quite fast when compared with public key encryption. In order to protect the data, the key needs to be secured. If a 3rd party was able to gain access to the key, they could decrypt any data that was encrypt with that data. For this reason, a secure channel is required to transfer the key if you need to transfer data between two points. For example, if you encrypted data on a CD and mail it to another party, the key must also be transferred to the second party so that they can decrypt the data. This is often done using e-mail or the telephone. In a lot of cases, sending the data using one method and the key using another method is enough to protect the data as an attacker would need to get both in order to decrypt the data. Public Key Encryption This method of encryption uses two keys. One key is used to encrypt data and the other key is used to decrypt data. The advantage of this is that the public key can be downloaded by anyone. Anyone with the public key can encrypt data that can only be decrypted using a private key. This means the public key does not need to be secured. The private key does need to be keep in a safe place. The advantage of using such a system is the private key is not required by the other party to perform encryption. Since the private key does not need to be transferred to the second party there is no risk of the private key being intercepted by a 3rd party. Public Key encryption is slower when compared with symmetric key so it is not always suitable for every application. The math used is complex but to put it simply it uses the modulus or remainder operator. For example, if you wanted to solve X mod 5 = 2, the possible solutions would be 2, 7, 12 and so on. The private key provides additional information which allows the problem to be solved easily. The math is more complex and uses much larger numbers than this but basically public and private key encryption rely on the modulus operator to work. Combing The Two There are two reasons you want to combine the two. The first is that often communication will be broken into two steps. Key exchange and data exchange. For key exchange, to protect the key used in data exchange it is often encrypted using public key encryption. Although slower than symmetric key encryption, this method ensures the key cannot accessed by a 3rd party while being transferred. Since the key has been transferred using a secure channel, a symmetric key can be used for data exchange. In some cases, data exchange may be done using public key encryption. If this is the case, often the data exchange will be done using a small key size to reduce the processing time. The second reason that both may be used is when a symmetric key is used and the key needs to be provided to multiple users. For example, if you are using encryption file system (EFS) this allows multiple users to access the same file, which includes recovery users. In order to make this possible, multiple copies of the same key are stored in the file and protected from being read by encrypting it with the public key of each user that requires access. References "Public-key cryptography" http://en.wikipedia.org/wiki/Public-k... "Encryption" http://en.wikipedia.org/wiki/Encryption
Views: 480835 itfreetraining
An introduction to linear feedback shift registers, and their use in generating pseudorandom numbers for Vernam ciphers. For more cryptography, subscribe to my channel: https://www.youtube.com/channel/UC1KV5WfubHTV6E7sVCnTidw
Views: 29667 Jeff Suzuki
Cryptography 101 - - XOR Cipher
XOR ciphers take advantage of Ascii encoding and basic bit switching operations. They are extremely fast, but not particularly secure when used alone, without a key exchange algorithm. XOR ciphers make up much of the basis of how modern encryption works. More Crypto 101: ADFVGX - https://www.youtube.com/watch?v=Y5-ory-Z25g Pigpen - https://www.youtube.com/watch?v=bUlIvx0fgV8 Homophonic Cipher - https://www.youtube.com/watch?v=sB_3fcO8G24 Vigenère Cipher - https://www.youtube.com/watch?v=QzizXgWGjcM Cracking Substitution Ciphers - https://www.youtube.com/watch?v=p99Wo_rr7OA Caesar shift and Atbash - https://www.youtube.com/watch?v=BbcYLI_3mNA Support me on Patreon if you are into that - https://www.patreon.com/laingsoft
Views: 9537 Charles Laing
Graph-theoretic tools for Boolean functions
On August 29, 2012, Prof. Pante Stanica from the Naval Postgraduate School, spoke on graph-theoretic tools for cryptographic Boolean functions. In this 50 minute talk, Prof Stanica discusses various properties of Boolean functions through the prism of graph theory. Cayley graphs and Nagy graphs are intorduced in this context, and new directions for further research are mentioned at the end of the talk. More details of parts of the talk can be found in his book with Thomas W. Cusick: "Cryptographic Boolean Functions and Applications," Academic Press - Elsevier, March 2009.
Views: 225 David Joyner
Symmetric Key Cryptography: The XOR Cipher
This is the fourth in a series about cryptography; an extremely important aspect of computer science and cyber security. It covers the XOR logical operation, that is the exclusive OR operation, explaining how it can be used to encrypt and decrypt a sequence of binary digits. XOR is an important process that is employed by many modern day ciphers. Using a spreadsheet, this video demonstrates how the XOR logical operation can be applied to a single character ASCII code to encrypt and decrypt it using the same symmetric key, and the same method.
Views: 309 Computer Science
Combinatorics of Boolean Functions, and Some Applications - Gil Kalai
Analysis and Beyond - Celebrating Jean Bourgain's Work and Impact May 23, 2016 More videos on http://video.ias.edu
Number Theory 4  Intro to Encryption
Part 3: Introduction to codes and an example or RSA public key encryption.
Boolean Searchable Symmetric Encryption with Worst Case Sub Linear Complexity
Paper by Seny Kamara and Tarik Moataz presented at Eurocrypt 2017. See https://www.iacr.org/cryptodb/data/paper.php?pubkey=28003
Views: 235 TheIACR
Xor Function Solution - Applied Cryptography
This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 7884 Udacity
Cryptography Primer Session 2 – Symmetric Primitives
This will be the second of six cryptography primer sessions exploring the basics of modern cryptography. In this session, we’ll explore symmetric ciphers, primitives, and protocols – including AES, cipher modes, hash functions, and message authentication. Subsequent sessions (on alternating Fridays) are expected to include the following topics. Depending on the interests of the participants, other topics may be included or substituted. • Integer asymmetric functions including BigNums, Diffie-Hellman, RSA, and DSA • Non-integer asymmetric functions including elliptic curves and lattice-based systems • Protocol properties including forward secrecy, crypto agility, and certificate management • Applications including zero-knowledge, secret sharing, homomorphic encryption, and election protocols
Views: 211 Microsoft Research
C/C++ Cryptography — XOR Encryption | Simple encryption Algorithm
simple program that uses xor encryption algorithm to encrypt a string. • Support me on Patreon: http://www.patreon.com/Zer0Mem0ry • Donate Bitcoin: 1JhSKGgRQmir8rRF4Sm5CP4fDDofKFAypd • Facebook: https://www.facebook.com/Zer0Mem0ry • Twitter: https://www.twitter.com/Zer0Mem0ry
Views: 15693 Zer0Mem0ry
Charles River Crypto Day - The Power of Negations in Cryptography
The study of monotonicity and negation complexity for Boolean functions has been prevalent in complexity theory as well as in computational learning theory, but little attention has been given to it in the cryptographic context. Recently, Goldreich and Izsak (2012) have initiated a study of whether cryptographic primitives can be monotone, and showed that one-way functions can be monotone (assuming they exist), but a pseudorandom generator cannot. In this work, we start by filling in the picture and proving that many other basic cryptographic primitives cannot be monotone. We then initiate a quantitative study of the power of negations, asking how many negations are required. We provide several lower bounds, some of them tight, for various cryptographic primitives and building blocks including one-way permutations, pseudorandom functions, small-bias generators, hard-core predicates, error-correcting codes, and randomness extractors. Among our results, we highlight the following. i) Unlike one-way functions, one-way permutations cannot be monotone. ii) We prove that pseudorandom functions require log n−O(1) negations (which is optimal up to the additive term). iii) Error-correcting codes with optimal distance parameters require log n−O(1) negations (again, optimal up to the additive term). iv) We prove a general result for monotone functions, showing a lower bound on the depth of any circuit with t negations on the bottom that computes a monotone function f in terms of the monotone circuit depth of f. This result addresses a question posed by Koroth and Sarma (2014) in the context of the circuit complexity of the Clique problem. Joint work with Siyao Guo, Igor Carboni Oliveira, and Alon Rosen.
Views: 239 Microsoft Research
Image Encryption and Decryption using Chaotic Key Sequence
Image Encryption and Decryption using Chaotic Key Sequence Generated by Sequence of Logistic Map and Sequence of States of Linear Feedback Shift Register This video project is done by: Potcharaphol Chat-anan (Aung) Tan Wei Jie, Chester Feng Wei Nicholas Koh Ming Xuan Jonathan Liem Zhuan Kim Chia Su Chi Faith
Views: 12444 Potcharaphol Chat-anan
Lecture 4: Stream Ciphers and Linear Feedback Shift Registers by Christof Paar
For slides, a problem set and more on learning cryptography, visit www.crypto-textbook.com
The Internet: Encryption & Public Keys
Mia Epner, who works on security for a US national intelligence agency, explains how cryptography allows for the secure transfer of data online. This educational video explains 256 bit encryption, public and private keys, SSL & TLS and HTTPS. Learn more at http://code.org/ Help us translate into your language: http://code.org/translate/videos Stay in touch with us! • on Twitter https://twitter.com/codeorg • on Facebook https://www.facebook.com/Code.org • on Instagram https://instagram.com/codeorg • on Tumblr https://blog.code.org • on LinkedIn https://www.linkedin.com/company/code... • on Google+ https://google.com/+codeorg Help us caption & translate this video! https://amara.org/v/HGaS/
Views: 225143 Code.org
Public Key Cryptography - Computerphile
Spies used to meet in the park to exchange code words, now things have moved on - Robert Miles explains the principle of Public/Private Key Cryptography note1: Yes, it should have been 'Obi Wan' not 'Obi One' :) note2: The string of 'garbage' text in the two examples should have been different to illustrate more clearly that there are two different systems in use. 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: 428733 Computerphile
Mathematical Ideas in Lattice Based Cryptography - Jill Pipher
2018 Program for Women and Mathematics Topic: Mathematical Ideas in Lattice Based Cryptography Speaker: Jill Pipher Affiliation: Brown University Date: May 21, 2018 For more videos, please visit http://video.ias.edu
Overview on S-Box Design Principles
Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in
Views: 28218 nptelhrd
Analysis of Boolean Functions. Part I | Ryan O'Donnell | Лекториум
Лекция: Analysis of Boolean Functions. Part I | Курс: Analysis of Boolean Functions | Лектор: Ryan O'Donnell | Организатор: Математическая лаборатория имени П.Л.Чебышева Смотрите это видео на Лекториуме: https://www.lektorium.tv/lecture/28290 Подписывайтесь на канал: https://www.lektorium.tv/ZJA Следите за новостями: https://vk.com/openlektorium https://www.facebook.com/openlektorium
Views: 1785 Лекториум
Discrete Mathematics - Lecture 05: Caesar Code Encryption
Caesar Code method in Data Encryption is discussed here with details of example calculation. Script and audio: Dr. Rajib L. Das Website: www.rldworld.com
Views: 182 RLD World
IGCSE Computer Science Tutorial: 1.4 (d) – Encryption
Candidates should be able to: • Show understanding of the use of encryption.
Views: 4745 Liam McQuay
What is AVALANCHE EFFECT? What does AVALANCHE EFFECT mean? AVALANCHE EFFECT meaning & explanation
What is AVALANCHE EFFECT? What does AVALANCHE EFFECT mean? AVALANCHE EFFECT meaning - AVALANCHE EFFECT definition - AVALANCHE EFFECT explanation. SUBSCRIBE to our Google Earth flights channel - http://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ?sub_confirmation=1 Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. In cryptography, the avalanche effect is the desirable property of cryptographic algorithms, typically block ciphers and cryptographic hash functions, wherein if an input is changed slightly (for example, flipping a single bit), the output changes significantly (e.g., half the output bits flip). In the case of high-quality block ciphers, such a small change in either the key or the plaintext should cause a drastic change in the ciphertext. The actual term was first used by Horst Feistel, although the concept dates back to at least Shannon's diffusion. If a block cipher or cryptographic hash function does not exhibit the avalanche effect to a significant degree, then it has poor randomization, and thus a cryptanalyst can make predictions about the input, being given only the output. This may be sufficient to partially or completely break the algorithm. Thus, the avalanche effect is a desirable condition from the point of view of the designer of the cryptographic algorithm or device. Constructing a cipher or hash to exhibit a substantial avalanche effect is one of the primary design objectives, and mathematically the construction takes advantage of butterfly effect. This is why most block ciphers are product ciphers. It is also why hash functions have large data blocks. Both of these features allow small changes to propagate rapidly through iterations of the algorithm, such that every bit of the output should depend on every bit of the input before the algorithm terminates. The strict avalanche criterion (SAC) is a formalization of the avalanche effect. It is satisfied if, whenever a single input bit is complemented, each of the output bits changes with a 50% probability. The SAC builds on the concepts of completeness and avalanche and was introduced by Webster and Tavares in 1985. Higher-order generalizations of SAC involve multiple input bits. Boolean functions which satisfy the highest order SAC are always bent functions, also called maximally nonlinear functions, also called "perfect nonlinear" functions.
Views: 946 The Audiopedia
Proofs in Cryptography: Lecture 7 Reduction Proof Example - PRF Family
Proofs in Cryptography Lecture 7 Reduction Proof Example - PRF Family ALPTEKİN KÜPÇÜ Assistant Professor of Computer Science and Engineering Koç University http://crypto.ku.edu.tr
Views: 2472 KOLT KU
PKI Components - CompTIA Security+ SY0-501 - 6.4
Security+ Training Course Index: http://professormesser.link/sy0501 Professor Messer’s Course Notes: http://professormesser.link/501cn Frequently Asked Questions: http://professormesser.link/faq - - - - - Creating a public key infrastructure requires extensive planning. In this video, you’ll learn about the most important components required to build a successful PKI. - - - - - 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: 21260 Professor Messer
Highly-Scalable Searchable Symmetric Encryption with Sup ...
Talk at crypto 2013. Authors: David Cash, Stanislaw Jarecki, Charanjit S. Jutla, Hugo Krawczyk, Marcel-Catalin Rosu, Michael Steiner
Views: 1188 TheIACR
Oracle Separation of BQP and the Polynomial Hierarchy
Avishay Tal (Stanford University) https://simons.berkeley.edu/talks/tbd-11 Boolean Devices
Views: 220 Simons Institute
Symmetric Key Ciphers
Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in
Views: 18287 nptelhrd
Presentation over Cryptographic Primitives (RC4) ( Personal-Portfolio )
Update: The simulation is now freely available on Google Play https://play.google.com/store/apps/details?id=air.rc4simulation&hl=en. Details: A presentation explaining the RC4 algorithm through animation. Coded with Flash AS3.0. The specification and required algorithms were already provided by the employer. My work in this project is on programming the interface, functioning and the required animations.
Views: 28096 Vishwas Gagrani
#6 cryptographic primitives - encryption ciphers
- symmetric - asymmetric - stream ciphers - CBC mode Exercise: combining cryptographic primitives to solve a specific problem.
Views: 263 ralienpp
What are security issues in Cryptography
www.hiteshChoudhary.com www.newdemy.com What are security issues in Cryptography? Why there is a need of Cryptography is a very important question. In the earlier times when one need to transfer any sensitive information, one can write it on paper and can seal it along with manual monitoring system i.e. one person guarding or protecting the information. But after the invention of radio, things got changed. One can tune into your radio without your knowledge and can collect all information. Just collecting the information is not a bug issue but one can modify the information as well. Information security attack is a broad term, so let’s make a few scenario examples to clarify it out on a broad level. Case 1 User A wants to transmit a file to user B. The file may contain some sensitive information like Bank passwords. User C, who is not authorized to read the file, is somehow monitor the transfer and captures a copy of the file during transmission. Case 2 User A wants to transmit a file to user B. User A gives some bank details to open and close new accounts. User C, intercepts the file and add User C’s information to be added and gets a new unauthorized bank account. User C can also delete some valid account information by altering the information. User B updates the details according to information passed by User A, having no idea that information was tempered on its way. Case 3 User A is just relaxing in this case. User C, who is an unauthorized person, just creates his own message and act as a User A and passes the information to User B. User B accepts the message and act according the message. It is totally up to User C that what he wants to do. User C can format all the information or add some backdoor information in the system and so on. Case 4 User C works for the company and due to some reasons C was fires from the company. User A asks the User B, who is an administrator in the company to lock all the access of User C’s account. But User C, creates some useless traffic and delays the message to reach to user B. User c makes a final access to the account and downloads the entire information to local or permanent access. After completing the work he allows the message to get passed. Case 5 A message is sent from user A to user B to purchase xyz share or xyz amount. Things didn’t went in right direction for User A and investment lose value. Now user A denies that he ever passed any message to user B to purchase any share. These are some of the broadly covered situations explaining the need of cryptography. Cryptography gives us a solution to all of these problems. We just have to utilize the concept and put it in some form of codes or protocols to implement it.
Views: 2396 Hitesh Choudhary
Applied Cryptography: Stream Ciphers (2/3)
Previous video: https://youtu.be/W39KqX0ZTbU Next video: https://youtu.be/_XBQeAnjjwk
Views: 2825 Leandro Junes
Bloom filter encryption and applications to efficient forward-secret 0-RTT key exchange
Technical talks from the Real World Crypto conference series.
Views: 1013 Real World Crypto
Proofs in Cryptography: Lecture 3 Reduction Proofs - What are they?
Proofs in Cryptography Lecture 3 Reduction Proofs - What are they? ALPTEKİN KÜPÇÜ Assistant Professor of Computer Science and Engineering Koç University http://crypto.ku.edu.tr
Views: 2434 KOLT KU
Decentralizing Attribute-Based Encryption
We present a Multi-Authority Attribute-Based Encryption (ABE) system. In our system, any party can become an authority and there is no requirement for any global coordination other than the creation of an initial set of common reference parameters. A party can simply act as an ABE authority by creating a public key and issuing private keys to different users that reflect their attributes. A user can encrypt data in terms of any boolean formula over attributes issued from any chosen set of authorities. Finally, our system does not require any central authority. In this talk, I will present our system and discuss its proof, which employs dual system encryption techniques. Our system uses bilinear groups of composite order, and we prove security under static assumptions in the random oracle model. This is joint work with Brent Waters.
Views: 1684 Microsoft Research
Congruence Modulo n Symmetry Proof
Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Congruence Modulo n Symmetry Proof
Views: 5678 The Math Sorcerer
Publicly Verifiable Boolean Query Over Outsourced Encrypted Data
Publicly Verifiable Boolean Query Over Outsourced Encrypted Data Get the Project Source Code Link : http://linkshrink.net/7TW6cv
Views: 379 1 Crore Projects
3rd BIU Winter School on Cryptography: Identity-Based Encryption and Variants - Dan Boneh
The 3rd Bar-Ilan Winter School on Cryptography: Bilinear Pairings in Cryptography, which was held between February 4th - 7th, 2013. The event's program: http://crypto.biu.ac.il/winterschool2013/schedule2013.pdf For All 2013 Winter school Lectures: http://www.youtube.com/playlist?list=PLXF_IJaFk-9C4p3b2tK7H9a9axOm3EtjA&feature=mh_lolz Dept. of Computer Science: http://www.cs.biu.ac.il/ Bar-Ilan University: http://www1.biu.ac.il/indexE.php
Views: 6103 barilanuniversity
Experiments with Exponential Sums over the Binary Field Part 2
Luis Medina, University of Puerto Rico Title: Experiments with Exponential Sums over the Binary Field. Let $\mathbb{F}$ be the binary field and $F({\bf X}) = F(X_1, \cdots, X_n)$ a polynomial in $n$ variables over $\mathbb{F}$. The exponential sum associated to $F$ over $\mathbb{F}$ is defined as $$ S(F)=\sum_{x_1,\cdots,x_n \in \mathbb{F}}(-1)^{F(x_1,\cdots, x_n)}. $$ Boolean functions (functions over $\mathbb{F}$) have many applications to cryptography and coding theory. In this talk, we present the study of exponential sums of boolean symmetric functions from the Experimental Mathematics perspective. In particular, we find recurrence relations they satisfy and attempt to get their exact values from these recurrences. Joint work with: Francis N. Castro and Ivelisse Rubio.
Attribute-based Encryption for Circuits
Vinod Vaikuntanathan, Massachusetts Institute of Technology The Mathematics of Modern Cryptography http://simons.berkeley.edu/talks/Vaikuntanathan-Wee-2015-07-06
Views: 5508 Simons Institute
Addition modulo and Multiplication modulo | Hindi | Discrete Mathematics- part-12
This video contains the basic of Group theory and basic operators like Implication will help you in various competitive exams like GATE , NET, PSU's etc
Dynamic Searchable Encryption via Blind Storage
Dynamic Searchable Symmetric Encryption allows a client to store a dynamic collection of encrypted documents with a server, and later quickly carry out keyword searches on these encrypted documents, while revealing minimal information to the server. In this paper we present a new dynamic SSE scheme that is simpler and more efficient than existing schemes while revealing less information to the server than prior schemes, achieving fully adaptive security against honest-but-curious servers. We implemented a prototype of our scheme and demonstrated its efficiency on datasets from prior work. Apart from its concrete efficiency, our scheme is also simpler: in particular, it does not require the server to support any operation other than upload and download of data. Thus the server in our scheme can be based solely on a cloud storage service, rather than a cloud computation service as well, as in prior work. In building our dynamic SSE scheme, we introduce a new primitive called Blind Storage, which allows a client to store a set of files on a remote server in such a way that the server does not learn how many files are stored, or the lengths of the individual files; as each file is retrieved, the server learns about its existence (and can notice the same file being downloaded subsequently), but the file’s name and contents are not revealed. This is a primitive with several applications other than SSE, and is of independent interest.
Views: 581 Microsoft Research