Comparison of Blowfish and Cast-128 Algorithms Using Encryption Quality, Key Sensitivity and Correlation Coefficient Analysis
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Blockchain Beyond Cryptocurrency Or Is Private Chain a Hoax Or How I Lose Money in Bitcoin but Still Decide to Get in the Research
Blockchain Beyond Cryptocurrency Or Is Private Chain a Hoax Or How I Lose Money in Bitcoin but still Decide to Get in the Research Hong Wan Edward P. Fitts Department of Industrial and Systems Engineering Sept 2019 In this talk: • Blockchain and trust • Different kinds of blockchain • Cases and Examples • Discussions First Things First https://images.app.goo.gl/JuNznV8dZKTaHWEf9 Disclaimer Block and Chain https://youtu.be/SSo_EIwHSd4 https://youtu.be/SSo_EIwHSd4 Blockchain Design Questions • Who can access data: Private vs. Public • Who can validate data/add block: Permissioned vs Permissionless • Consensus to be used: Trade-off among security and efficiency. https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=2ahUKEwinjN2s7_DkAhXlmeAKHXxhAIUQjRx6BAgBEAQ&url=ht tps%3A%2F%2F101blockchains.com%2Fconsensus-algorithms-blockchain%2F&psig=AOvVaw23pKh4qS8W_xgyajJ3aFl9&ust=1569669093339830 Bad News First • “Private blockchains are completely uninteresting… -- the only reason to operate one is to ride on the blockchain hype…” Bruce Schneier Tonight we will talk about cryptocurrencies… .everything you don’t understand money combined by everything you don’t understand about computers…. Cryptocurrencies: Last Week Tonight with John Oliver (HBO) https://www.schneier.com/blog/archives/2019/02/blockchain_and_.html http://shorturl.at/ahsRU, shorturl.at/gETV2 https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=2ahUKEwj- https://d279m997dpfwgl.cloudfront.net/wp/2017/11/Trustp72L7vDkAhVjQt8KHU18CjsQjRx6BAgBEAQ&url=https%3A%2F%2Fwww.wbur.org%2Fonpoint%2F2017%2F11%2F20%2Fwho-can-cropped.jpg-you- -
Impossible Differentials in Twofish
Twofish Technical Report #5 Impossible differentials in Twofish Niels Ferguson∗ October 19, 1999 Abstract We show how an impossible-differential attack, first applied to DEAL by Knudsen, can be applied to Twofish. This attack breaks six rounds of the 256-bit key version using 2256 steps; it cannot be extended to seven or more Twofish rounds. Keywords: Twofish, cryptography, cryptanalysis, impossible differential, block cipher, AES. Current web site: http://www.counterpane.com/twofish.html 1 Introduction 2.1 Twofish as a pure Feistel cipher Twofish is one of the finalists for the AES [SKW+98, As mentioned in [SKW+98, section 7.9] and SKW+99]. In [Knu98a, Knu98b] Lars Knudsen used [SKW+99, section 7.9.3] we can rewrite Twofish to a 5-round impossible differential to attack DEAL. be a pure Feistel cipher. We will demonstrate how Eli Biham, Alex Biryukov, and Adi Shamir gave the this is done. The main idea is to save up all the ro- technique the name of `impossible differential', and tations until just before the output whitening, and applied it with great success to Skipjack [BBS99]. apply them there. We will use primes to denote the In this report we show how Knudsen's attack can values in our new representation. We start with the be applied to Twofish. We use the notation from round values: [SKW+98] and [SKW+99]; readers not familiar with R0 = ROL(Rr;0; (r + 1)=2 ) the notation should consult one of these references. r;0 b c R0 = ROR(Rr;1; (r + 1)=2 ) r;1 b c R0 = ROL(Rr;2; r=2 ) 2 The attack r;2 b c R0 = ROR(Rr;3; r=2 ) r;3 b c Knudsen's 5-round impossible differential works for To get the same output we update the rule to com- any Feistel cipher where the round function is in- pute the output whitening. -
Block Ciphers
Block Ciphers Chester Rebeiro IIT Madras CR STINSON : chapters 3 Block Cipher KE KD untrusted communication link Alice E D Bob #%AR3Xf34^$ “Attack at Dawn!!” message encryption (ciphertext) decryption “Attack at Dawn!!” Encryption key is the same as the decryption key (KE = K D) CR 2 Block Cipher : Encryption Key Length Secret Key Plaintext Ciphertext Block Cipher (Encryption) Block Length • A block cipher encryption algorithm encrypts n bits of plaintext at a time • May need to pad the plaintext if necessary • y = ek(x) CR 3 Block Cipher : Decryption Key Length Secret Key Ciphertext Plaintext Block Cipher (Decryption) Block Length • A block cipher decryption algorithm recovers the plaintext from the ciphertext. • x = dk(y) CR 4 Inside the Block Cipher PlaintextBlock (an iterative cipher) Key Whitening Round 1 key1 Round 2 key2 Round 3 key3 Round n keyn Ciphertext Block • Each round has the same endomorphic cryptosystem, which takes a key and produces an intermediate ouput • Size of the key is huge… much larger than the block size. CR 5 Inside the Block Cipher (the key schedule) PlaintextBlock Secret Key Key Whitening Round 1 Round Key 1 Round 2 Round Key 2 Round 3 Round Key 3 Key Expansion Expansion Key Key Round n Round Key n Ciphertext Block • A single secret key of fixed size used to generate ‘round keys’ for each round CR 6 Inside the Round Function Round Input • Add Round key : Add Round Key Mixing operation between the round input and the round key. typically, an ex-or operation Confusion Layer • Confusion layer : Makes the relationship between round Diffusion Layer input and output complex. -
Report on the AES Candidates
Rep ort on the AES Candidates 1 2 1 3 Olivier Baudron , Henri Gilb ert , Louis Granb oulan , Helena Handschuh , 4 1 5 1 Antoine Joux , Phong Nguyen ,Fabrice Noilhan ,David Pointcheval , 1 1 1 1 Thomas Pornin , Guillaume Poupard , Jacques Stern , and Serge Vaudenay 1 Ecole Normale Sup erieure { CNRS 2 France Telecom 3 Gemplus { ENST 4 SCSSI 5 Universit e d'Orsay { LRI Contact e-mail: [email protected] Abstract This do cument rep orts the activities of the AES working group organized at the Ecole Normale Sup erieure. Several candidates are evaluated. In particular we outline some weaknesses in the designs of some candidates. We mainly discuss selection criteria b etween the can- didates, and make case-by-case comments. We nally recommend the selection of Mars, RC6, Serp ent, ... and DFC. As the rep ort is b eing nalized, we also added some new preliminary cryptanalysis on RC6 and Crypton in the App endix which are not considered in the main b o dy of the rep ort. Designing the encryption standard of the rst twentyyears of the twenty rst century is a challenging task: we need to predict p ossible future technologies, and wehavetotake unknown future attacks in account. Following the AES pro cess initiated by NIST, we organized an op en working group at the Ecole Normale Sup erieure. This group met two hours a week to review the AES candidates. The present do cument rep orts its results. Another task of this group was to up date the DFC candidate submitted by CNRS [16, 17] and to answer questions which had b een omitted in previous 1 rep orts on DFC. -
Episode 230: Click Here to Kill Everybody
Episode 230: Click Here to Kill Everybody Stewart Baker: [00:00:03] Welcome to Episode 230 of The Cyberlaw Podcast brought to you by Steptoe & Johnson. We are back and full of energy. Thank you for joining us. We're lawyers talking about technology, security, privacy, and government. And if you want me to talk about hiking through the rain forest of Costa Rica and just how tough my six-year-old granddaughter is, I'm glad to do that too. But today I'm joined by our guest interviewee Bruce Schneier, an internationally renowned technologist, privacy and security guru, and the author of the new book, Click Here to Kill Everybody: Security and Survival in a Hyper-Connected World. We'll be talking to him shortly. For the News Roundup, we have Jamil Jaffer, who's the founder of the estimable and ever-growing National Security Institute. He's also an adjunct professor at George Mason University. Welcome, Jamil. Jamil Jaffer: [00:00:57] Thanks, Stewart. Good to be here. Stewart Baker: [00:00:58] And David Kris, formerly the assistant attorney general in charge of the Justice Department's National Security Division. David, welcome. David Kris: [00:01:07] Thank, you. Good to be here. Stewart Baker: [00:01:08] And he is with his partner in their latest venture, Nate Jones, veteran of the Justice Department, the National Security Council, and Microsoft where he was an assistant general counsel. Nate, welcome. Nate Jones: [00:01:23] Thank you. Stewart Baker: [00:01:25] I'm Stewart Baker, formerly with the NSA and DHS and the host of today's program. -
Bruce Schneier 2
Committee on Energy and Commerce U.S. House of Representatives Witness Disclosure Requirement - "Truth in Testimony" Required by House Rule XI, Clause 2(g)(5) 1. Your Name: Bruce Schneier 2. Your Title: none 3. The Entity(ies) You are Representing: none 4. Are you testifying on behalf of the Federal, or a State or local Yes No government entity? X 5. Please list any Federal grants or contracts, or contracts or payments originating with a foreign government, that you or the entity(ies) you represent have received on or after January 1, 2015. Only grants, contracts, or payments related to the subject matter of the hearing must be listed. 6. Please attach your curriculum vitae to your completed disclosure form. Signatur Date: 31 October 2017 Bruce Schneier Background Bruce Schneier is an internationally renowned security technologist, called a security guru by the Economist. He is the author of 14 books—including the New York Times best-seller Data and Goliath: The Hidden Battles to Collect Your Data and Control Your World—as well as hundreds of articles, essays, and academic papers. His influential newsletter Crypto-Gram and blog Schneier on Security are read by over 250,000 people. Schneier is a fellow at the Berkman Klein Center for Internet and Society at Harvard University, a Lecturer in Public Policy at the Harvard Kennedy School, a board member of the Electronic Frontier Foundation and the Tor Project, and an advisory board member of EPIC and VerifiedVoting.org. He is also a special advisor to IBM Security and the Chief Technology Officer of IBM Resilient. -
Data Encryption Standard
Data Encryption Standard The Data Encryption Standard (DES /ˌdiːˌiːˈɛs, dɛz/) is a Data Encryption Standard symmetric-key algorithm for the encryption of electronic data. Although insecure, it was highly influential in the advancement of modern cryptography. Developed in the early 1970s atIBM and based on an earlier design by Horst Feistel, the algorithm was submitted to the National Bureau of Standards (NBS) following the agency's invitation to propose a candidate for the protection of sensitive, unclassified electronic government data. In 1976, after consultation with theNational Security Agency (NSA), the NBS eventually selected a slightly modified version (strengthened against differential cryptanalysis, but weakened against brute-force attacks), which was published as an official Federal Information Processing Standard (FIPS) for the United States in 1977. The publication of an NSA-approved encryption standard simultaneously resulted in its quick international adoption and widespread academic scrutiny. Controversies arose out of classified The Feistel function (F function) of DES design elements, a relatively short key length of the symmetric-key General block cipher design, and the involvement of the NSA, nourishing Designers IBM suspicions about a backdoor. Today it is known that the S-boxes that had raised those suspicions were in fact designed by the NSA to First 1975 (Federal Register) actually remove a backdoor they secretly knew (differential published (standardized in January 1977) cryptanalysis). However, the NSA also ensured that the key size was Derived Lucifer drastically reduced such that they could break it by brute force from [2] attack. The intense academic scrutiny the algorithm received over Successors Triple DES, G-DES, DES-X, time led to the modern understanding of block ciphers and their LOKI89, ICE cryptanalysis. -
A Lightweight Encryption Algorithm for Secure Internet of Things
Pre-Print Version, Original article is available at (IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 8, No. 1, 2017 SIT: A Lightweight Encryption Algorithm for Secure Internet of Things Muhammad Usman∗, Irfan Ahmedy, M. Imran Aslamy, Shujaat Khan∗ and Usman Ali Shahy ∗Faculty of Engineering Science and Technology (FEST), Iqra University, Defence View, Karachi-75500, Pakistan. Email: fmusman, [email protected] yDepartment of Electronic Engineering, NED University of Engineering and Technology, University Road, Karachi 75270, Pakistan. Email: firfans, [email protected], [email protected] Abstract—The Internet of Things (IoT) being a promising and apply analytics to share the most valuable data with the technology of the future is expected to connect billions of devices. applications. The IoT is taking the conventional internet, sensor The increased number of communication is expected to generate network and mobile network to another level as every thing mountains of data and the security of data can be a threat. The will be connected to the internet. A matter of concern that must devices in the architecture are essentially smaller in size and be kept under consideration is to ensure the issues related to low powered. Conventional encryption algorithms are generally confidentiality, data integrity and authenticity that will emerge computationally expensive due to their complexity and requires many rounds to encrypt, essentially wasting the constrained on account of security and privacy [4]. energy of the gadgets. Less complex algorithm, however, may compromise the desired integrity. In this paper we propose a A. Applications of IoT: lightweight encryption algorithm named as Secure IoT (SIT). -
Identifying Open Research Problems in Cryptography by Surveying Cryptographic Functions and Operations 1
International Journal of Grid and Distributed Computing Vol. 10, No. 11 (2017), pp.79-98 http://dx.doi.org/10.14257/ijgdc.2017.10.11.08 Identifying Open Research Problems in Cryptography by Surveying Cryptographic Functions and Operations 1 Rahul Saha1, G. Geetha2, Gulshan Kumar3 and Hye-Jim Kim4 1,3School of Computer Science and Engineering, Lovely Professional University, Punjab, India 2Division of Research and Development, Lovely Professional University, Punjab, India 4Business Administration Research Institute, Sungshin W. University, 2 Bomun-ro 34da gil, Seongbuk-gu, Seoul, Republic of Korea Abstract Cryptography has always been a core component of security domain. Different security services such as confidentiality, integrity, availability, authentication, non-repudiation and access control, are provided by a number of cryptographic algorithms including block ciphers, stream ciphers and hash functions. Though the algorithms are public and cryptographic strength depends on the usage of the keys, the ciphertext analysis using different functions and operations used in the algorithms can lead to the path of revealing a key completely or partially. It is hard to find any survey till date which identifies different operations and functions used in cryptography. In this paper, we have categorized our survey of cryptographic functions and operations in the algorithms in three categories: block ciphers, stream ciphers and cryptanalysis attacks which are executable in different parts of the algorithms. This survey will help the budding researchers in the society of crypto for identifying different operations and functions in cryptographic algorithms. Keywords: cryptography; block; stream; cipher; plaintext; ciphertext; functions; research problems 1. Introduction Cryptography [1] in the previous time was analogous to encryption where the main task was to convert the readable message to an unreadable format. -
(SAC)25 – a Retrospective
(SAC)25 – A Retrospective Carlisle Adams August 16, 2018 Beginnings Stafford Tavares Idea (early 1990s): • Canadian venue for crypto research • Small, friendly workshop • “discussion atmosphere” What to call it? • Stafford and one of his students, Art Webster, defined a property that they called the “Strict Avalanche Criterion” (SAC) in a paper published at Crypto 1985 – SAC is a formalization of the “avalanche effect” (a concept explored by Shannon and named by Feistel) and incorporates the notion of “completeness” Avalanche Small disturbance leads to large, unpredictable change SAC: if a single input bit is complemented, each output bit changes with probability p = 0.5 http://nsidc.org/cryosphere/snow/science/avalanches.html What to call the workshop? • “Avalanche effect” and “SAC” were fundamental and important work for symmetric cipher design (particularly s-box design), but Crypto and Eurocrypt were receiving lots of submissions from many other exciting advances in the field (zero knowledge protocols, secret sharing schemes, digital signatures, elliptic curve computations, etc., etc.) • “Selected Areas in Cryptography” (SAC) Organizers of the first SAC Workshop Stafford Tavares Henk Meijer Paul Van Oorschot Carlisle Adams Walter Light Hall Queen’s University at Kingston May 5-6, 1994 Governance • SAC Organizing Board – 9 members, each serving a 3-year term. One member is the Board Chair. – Each year, the terms of 3 members end. Each of these members may be replaced, or may serve another term. • SAC Conference – 3 permanent topics, plus a 4th topic that can vary from year to year. • SAC Co-Chairs – Normally 2 fully-cooperating co-chairs, although from 2001 typically one (Canadian) has primary responsibility for local arrangements, and one (residing outside Canada) focuses on the technical program. -
Designing Encryption Algorithms for Optimal Software Speed on the Intel Pentium Processor
Fast Software Encryption: Designing Encryption Algorithms for Optimal Software Speed on the Intel Pentium Processor Bruce Schneier Doug Whiting Counterpane Systems Stac Electronics 101 E Minnehaha Parkway 12636 High Bluff Drive Minneapolis, MN 55419 San Diego, CA 92130 [email protected] [email protected] Abstract. Most encryption algorithms are designed without regard to their performance on top-of-the-line microprocessors. This paper dis- cusses general optimization principles algorithms designers should keep in mind when designing algorithms, and analyzes the performance of RC4, SEAL, RC5, Blowfish, and Khufu/Khafre on the Intel Pentium with respect to those principles. Finally, we suggest directions for algo- rithm design, and give example algorithms, that take performance into account. 1 Overview The principal goal guiding the design of any encryption algorithm must be se- curity. In the real world, however, performance and implementation cost are always of concern. The increasing need for secure digital communication and the incredible processing power of desktop computers make performing software bulk encryption both more desirable and more feasible than ever. The purpose of this paper is to discuss low-level software optimization tech- niques and how they should be applied in the design of encryption algorithms. General design principles are presented that apply to almost all modern CPUs, but specific attention is also given to relevant characteristics of the ubiquitous Intel X86 CPU family (e.g., 486, Pentium, Pentium Pro). Several well-known algorithms are examined to show where these principles are violated, leading to sub-optimal performance. This paper concerns itself with number of clock cy- cles per byte encrypted|given a basic encryption algorithm \style." Factors of two, three, four, or more in speed can be easily obtained by careful design and implementation, and such speedups are very significant in the real world. -
A Novel Construction of Efficient Substitution-Boxes Using Cubic
entropy Article A Novel Construction of Efficient Substitution-Boxes Using Cubic Fractional Transformation Amjad Hussain Zahid 1,2, Muhammad Junaid Arshad 2 and Musheer Ahmad 3,* 1 Department of Computer Science, University of Management and Technology, Lahore 54000, Pakistan; [email protected] 2 Department of Computer Science, University of Engineering and Technology, Lahore 54000, Pakistan; [email protected] 3 Department of Computer Engineering, Jamia Millia Islamia, New Delhi 110025, India * Correspondence: [email protected]; Tel.: +91-112-698-0281 Received: 27 January 2019; Accepted: 28 February 2019; Published: 5 March 2019 Abstract: A symmetric block cipher employing a substitution–permutation duo is an effective technique for the provision of information security. For substitution, modern block ciphers use one or more substitution boxes (S-Boxes). Certain criteria and design principles are fulfilled and followed for the construction of a good S-Box. In this paper, an innovative technique to construct substitution-boxes using our cubic fractional transformation (CFT) is presented. The cryptographic strength of the proposed S-box is critically evaluated against the state of the art performance criteria of strong S-boxes, including bijection, nonlinearity, bit independence criterion, strict avalanche effect, and linear and differential approximation probabilities. The performance results of the proposed S-Box are compared with recently investigated S-Boxes to prove its cryptographic strength. The simulation and comparison analyses validate that the proposed S-Box construction method has adequate efficacy to generate efficient candidate S-Boxes for usage in block ciphers. Keywords: substitution box; cubic fractional transformation; block ciphers; security 1. Introduction Cryptography helps individuals and organizations to protect their data.