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The First Biclique Cryptanalysis of Serpent-256
The First Biclique Cryptanalysis of Serpent-256 Gabriel C. de Carvalho1, Luis A. B. Kowada1 1Instituto de Computac¸ao˜ – Universidade Federal Fluminense (UFF) – Niteroi´ – RJ – Brazil Abstract. The Serpent cipher was one of the finalists of the AES process and as of today there is no method for finding the key with fewer attempts than that of an exhaustive search of all possible keys, even when using known or chosen plaintexts for an attack. This work presents the first two biclique attacks for the full-round Serpent-256. The first uses a dimension 4 biclique while the second uses a dimension 8 biclique. The one with lower dimension covers nearly 4 complete rounds of the cipher, which is the reason for the lower time complex- ity when compared with the other attack (which covers nearly 3 rounds of the cipher). On the other hand, the second attack needs a lot less pairs of plain- texts for it to be done. The attacks require 2255:21 and 2255:45 full computations of Serpent-256 using 288 and 260 chosen ciphertexts respectively with negligible memory. 1. Introduction The Serpent cipher is, along with MARS, RC6, Twofish and Rijindael, one of the AES process finalists [Nechvatal et al. 2001] and has not had, since its proposal, its full round versions attacked. It is a Substitution Permutation Network (SPN) with 32 rounds, 128 bit block size and accepts keys of sizes 128, 192 and 256 bits. Serpent has been targeted by several cryptanalysis [Kelsey et al. 2000, Biham et al. 2001b, Biham et al. -
Multiple New Formulas for Cipher Performance Computing
International Journal of Network Security, Vol.20, No.4, PP.788-800, July 2018 (DOI: 10.6633/IJNS.201807 20(4).21) 788 Multiple New Formulas for Cipher Performance Computing Youssef Harmouch1, Rachid Elkouch1, Hussain Ben-azza2 (Corresponding author: Youssef Harmouch) Department of Mathematics, Computing and Networks, National Institute of Posts and Telecommunications1 10100, Allal El Fassi Avenue, Rabat, Morocco (Email:[email protected] ) Department of Industrial and Production Engineering, Moulay Ismail University2 National High School of Arts and Trades, Mekns, Morocco (Received Apr. 03, 2017; revised and accepted July 17, 2017) Abstract are not necessarily commensurate properties. For exam- ple, an online newspaper will be primarily interested in Cryptography is a science that focuses on changing the the integrity of their information while a financial stock readable information to unrecognizable and useless data exchange network may define their security as real-time to any unauthorized person. This solution presents the availability and information privacy [14, 23]. This means main core of network security, therefore the risk analysis that, the many facets of the attribute must all be iden- for using a cipher turn out to be an obligation. Until now, tified and adequately addressed. Furthermore, the secu- the only platform for providing each cipher resistance is rity attributes are terms of qualities, thus measuring such the cryptanalysis study. This cryptanalysis can make it quality terms need a unique identification for their inter- hard to compare ciphers because each one is vulnerable to pretations meaning [20, 24]. Besides, the attributes can a different kind of attack that is often very different from be interdependent. -
MD5 Collisions the Effect on Computer Forensics April 2006
Paper MD5 Collisions The Effect on Computer Forensics April 2006 ACCESS DATA , ON YOUR RADAR MD5 Collisions: The Impact on Computer Forensics Hash functions are one of the basic building blocks of modern cryptography. They are used for everything from password verification to digital signatures. A hash function has three fundamental properties: • It must be able to easily convert digital information (i.e. a message) into a fixed length hash value. • It must be computationally impossible to derive any information about the input message from just the hash. • It must be computationally impossible to find two files to have the same hash. A collision is when you find two files to have the same hash. The research published by Wang, Feng, Lai and Yu demonstrated that MD5 fails this third requirement since they were able to generate two different messages that have the same hash. In computer forensics hash functions are important because they provide a means of identifying and classifying electronic evidence. Because hash functions play a critical role in evidence authentication, a judge and jury must be able trust the hash values to uniquely identify electronic evidence. A hash function is unreliable when you can find any two messages that have the same hash. Birthday Paradox The easiest method explaining a hash collision is through what is frequently referred to as the Birthday Paradox. How many people one the street would you have to ask before there is greater than 50% probability that one of those people will share your birthday (same day not the same year)? The answer is 183 (i.e. -
Serpent: a Proposal for the Advanced Encryption Standard
Serpent: A Proposal for the Advanced Encryption Standard Ross Anderson1 Eli Biham2 Lars Knudsen3 1 Cambridge University, England; email [email protected] 2 Technion, Haifa, Israel; email [email protected] 3 University of Bergen, Norway; email [email protected] Abstract. We propose a new block cipher as a candidate for the Ad- vanced Encryption Standard. Its design is highly conservative, yet still allows a very efficient implementation. It uses S-boxes similar to those of DES in a new structure that simultaneously allows a more rapid avalanche, a more efficient bitslice implementation, and an easy anal- ysis that enables us to demonstrate its security against all known types of attack. With a 128-bit block size and a 256-bit key, it is as fast as DES on the market leading Intel Pentium/MMX platforms (and at least as fast on many others); yet we believe it to be more secure than three-key triple-DES. 1 Introduction For many applications, the Data Encryption Standard algorithm is nearing the end of its useful life. Its 56-bit key is too small, as shown by a recent distributed key search exercise [28]. Although triple-DES can solve the key length problem, the DES algorithm was also designed primarily for hardware encryption, yet the great majority of applications that use it today implement it in software, where it is relatively inefficient. For these reasons, the US National Institute of Standards and Technology has issued a call for a successor algorithm, to be called the Advanced Encryption Standard or AES. -
Serpenttools Documentation
serpentTools Documentation The serpentTools developer team Feb 20, 2020 CONTENTS: 1 Project Overview 3 2 Installation 7 3 Changelog 11 4 Examples 19 5 File-parsing API 77 6 Containers 97 7 Samplers 129 8 Settings 137 9 Miscellaneous 143 10 Variable Groups 147 11 Command Line Interface 161 12 Developer’s Guide 165 13 License 201 14 Developer Team 203 15 Glossary 205 16 Indices and tables 207 Bibliography 209 Index 211 i ii serpentTools Documentation A suite of parsers designed to make interacting with SERPENT [serpent] output files simple and flawless. The SERPENT Monte Carlo code is developed by VTT Technical Research Centre of Finland, Ltd. More information, including distribution and licensing of SERPENT can be found at http://montecarlo.vtt.fi The Annals of Nuclear Energy article should be cited for all work using SERPENT. Preferred citation for attribution Andrew Johnson, Dan Kotlyar, Gavin Ridley, Stefano Terlizzi, & Paul Romano. (2018, June 29). “serpent-tools: A collection of parsing tools and data containers to make interacting with SERPENT outputs easy, intuitive, and flawless.,”. CONTENTS: 1 serpentTools Documentation 2 CONTENTS: CHAPTER ONE PROJECT OVERVIEW The serpentTools package contains a variety of parsing utilities, each designed to read a specific output from the SERPENT Monte Carlo code [serpent]. Many of the parsing utilities store the outputs in custom container objects, while other store or return a collection of arrays. This page gives an overview of what files are currently supported, including links to examples and relevant documentation. Unless otherwise noted, all the files listed below can be read using serpentTools.read(). -
Differential Factors: Improved Attacks on Serpent
Cryptographic Properties of S-boxes Differential Factors Improved Attacks on Serpent Conclusion Differential Factors: Improved Attacks on Serpent Cihangir TEZCAN and Ferruh Ozbudak¨ Department of Mathematics Middle East Technical University Institute of Applied Mathematics Department of Cryptography Middle East Technical University LightSEC 2014 Istanbul,_ Turkey Cihangir TEZCAN and Ferruh Ozbudak¨ Differential Factors: Improved Attacks on Serpent Cryptographic Properties of S-boxes Differential Factors Improved Attacks on Serpent Conclusion Outline 1 Cryptographic Properties of S-boxes 2 Differential Factors 3 Improved Attacks on Serpent 4 Conclusion Cihangir TEZCAN and Ferruh Ozbudak¨ Differential Factors: Improved Attacks on Serpent Cryptographic Properties of S-boxes Differential Factors Improved Attacks on Serpent Conclusion S-box Properties and Cryptanalysis Confusion layer of cryptographic algorithms mostly consists of S-boxes. S-box Properties and Cryptanalysis 1 Differential Uniformity => Differential Cryptanalysis 2 Non-linear Uniformity => Linear Cryptanalysis 3 Branch Number => Algebraic and Cube Attacks 4 Number of Shares => Side-Channel Attacks, DPA 5 Undisturbed Bits => Truncated, Impossible, Improbable Differential Cryptanalysis Cihangir TEZCAN and Ferruh Ozbudak¨ Differential Factors: Improved Attacks on Serpent Example (Serpent S1) 1 Input: 4x => Output: ?1?? 2 Input: 8x => Output: ?1?? 3 Input: Cx => Output: ?0?? 4 Output: 1x => Input: 1??? 5 Output: 4x => Input: 1??? 6 Output: 5x => Input: 0??? Cryptographic Properties of S-boxes -
Network Security Chapter 8
Network Security Chapter 8 Network security problems can be divided roughly into 4 closely intertwined areas: secrecy (confidentiality), authentication, nonrepudiation, and integrity control. Question: what does non-repudiation mean? What does “integrity” mean? • Cryptography • Symmetric-Key Algorithms • Public-Key Algorithms • Digital Signatures • Management of Public Keys • Communication Security • Authentication Protocols • Email Security -- skip • Web Security • Social Issues -- skip Revised: August 2011 CN5E by Tanenbaum & Wetherall, © Pearson Education-Prentice Hall and D. Wetherall, 2011 Network Security Security concerns a variety of threats and defenses across all layers Application Authentication, Authorization, and non-repudiation Transport End-to-end encryption Network Firewalls, IP Security Link Packets can be encrypted on data link layer basis Physical Wireless transmissions can be encrypted CN5E by Tanenbaum & Wetherall, © Pearson Education-Prentice Hall and D. Wetherall, 2011 Network Security (1) Some different adversaries and security threats • Different threats require different defenses CN5E by Tanenbaum & Wetherall, © Pearson Education-Prentice Hall and D. Wetherall, 2011 Cryptography Cryptography – 2 Greek words meaning “Secret Writing” Vocabulary: • Cipher – character-for-character or bit-by-bit transformation • Code – replaces one word with another word or symbol Cryptography is a fundamental building block for security mechanisms. • Introduction » • Substitution ciphers » • Transposition ciphers » • One-time pads -
Modes of Operation for Compressed Sensing Based Encryption
Modes of Operation for Compressed Sensing based Encryption DISSERTATION zur Erlangung des Grades eines Doktors der Naturwissenschaften Dr. rer. nat. vorgelegt von Robin Fay, M. Sc. eingereicht bei der Naturwissenschaftlich-Technischen Fakultät der Universität Siegen Siegen 2017 1. Gutachter: Prof. Dr. rer. nat. Christoph Ruland 2. Gutachter: Prof. Dr.-Ing. Robert Fischer Tag der mündlichen Prüfung: 14.06.2017 To Verena ... s7+OZThMeDz6/wjq29ACJxERLMATbFdP2jZ7I6tpyLJDYa/yjCz6OYmBOK548fer 76 zoelzF8dNf /0k8H1KgTuMdPQg4ukQNmadG8vSnHGOVpXNEPWX7sBOTpn3CJzei d3hbFD/cOgYP4N5wFs8auDaUaycgRicPAWGowa18aYbTkbjNfswk4zPvRIF++EGH UbdBMdOWWQp4Gf44ZbMiMTlzzm6xLa5gRQ65eSUgnOoZLyt3qEY+DIZW5+N s B C A j GBttjsJtaS6XheB7mIOphMZUTj5lJM0CDMNVJiL39bq/TQLocvV/4inFUNhfa8ZM 7kazoz5tqjxCZocBi153PSsFae0BksynaA9ZIvPZM9N4++oAkBiFeZxRRdGLUQ6H e5A6HFyxsMELs8WN65SCDpQNd2FwdkzuiTZ4RkDCiJ1Dl9vXICuZVx05StDmYrgx S6mWzcg1aAsEm2k+Skhayux4a+qtl9sDJ5JcDLECo8acz+RL7/ ovnzuExZ3trm+O 6GN9c7mJBgCfEDkeror5Af4VHUtZbD4vALyqWCr42u4yxVjSj5fWIC9k4aJy6XzQ cRKGnsNrV0ZcGokFRO+IAcuWBIp4o3m3Amst8MyayKU+b94VgnrJAo02Fp0873wa hyJlqVF9fYyRX+couaIvi5dW/e15YX/xPd9hdTYd7S5mCmpoLo7cqYHCVuKWyOGw ZLu1ziPXKIYNEegeAP8iyeaJLnPInI1+z4447IsovnbgZxM3ktWO6k07IOH7zTy9 w+0UzbXdD/qdJI1rENyriAO986J4bUib+9sY/2/kLlL7nPy5Kxg3 Et0Fi3I9/+c/ IYOwNYaCotW+hPtHlw46dcDO1Jz0rMQMf1XCdn0kDQ61nHe5MGTz2uNtR3bty+7U CLgNPkv17hFPu/lX3YtlKvw04p6AZJTyktsSPjubqrE9PG00L5np1V3B/x+CCe2p niojR2m01TK17/oT1p0enFvDV8C351BRnjC86Z2OlbadnB9DnQSP3XH4JdQfbtN8 BXhOglfobjt5T9SHVZpBbzhDzeXAF1dmoZQ8JhdZ03EEDHjzYsXD1KUA6Xey03wU uwnrpTPzD99cdQM7vwCBdJnIPYaD2fT9NwAHICXdlp0pVy5NH20biAADH6GQr4Vc -
P4-3200-Gentoo.Pdf
p4-3200-gentoo libgcrypt Ciphers: Absolute Time by Data Length 1 0.1 0.01 0.001 Seconds 0.0001 1e-05 1e-06 10 100 1000 10000 100000 1000000 Data Length in Bytes Rijndael Serpent Twofish Blowfish CAST5 3DES p4-3200-gentoo libgcrypt Ciphers: Speed by Data Length 25 20 15 10 Megabyte / Second 5 0 10 100 1000 10000 100000 1000000 Data Length in Bytes Rijndael Serpent Twofish Blowfish CAST5 3DES p4-3200-gentoo libmcrypt Ciphers: Absolute Time by Data Length 1 0.1 0.01 Seconds 0.001 0.0001 10 100 1000 10000 100000 1000000 Data Length in Bytes Rijndael Twofish xTEA Loki97 GOST 3DES Serpent CAST6 Safer+ Blowfish CAST5 p4-3200-gentoo libmcrypt Ciphers: Speed by Data Length 45 40 35 30 25 20 Megabyte / Second 15 10 5 0 10 100 1000 10000 100000 1000000 Data Length in Bytes Rijndael Twofish xTEA Loki97 GOST 3DES Serpent CAST6 Safer+ Blowfish CAST5 p4-3200-gentoo Botan Ciphers: Absolute Time by Data Length 1 0.1 0.01 0.001 Seconds 0.0001 1e-05 1e-06 10 100 1000 10000 100000 1000000 Data Length in Bytes Rijndael Twofish GOST Blowfish 3DES Serpent CAST6 xTEA CAST5 p4-3200-gentoo Botan Ciphers: Speed by Data Length 40 35 30 25 20 Megabyte / Second 15 10 5 0 10 100 1000 10000 100000 1000000 Data Length in Bytes Rijndael Twofish GOST Blowfish 3DES Serpent CAST6 xTEA CAST5 p4-3200-gentoo Crypto++ Ciphers: Absolute Time by Data Length 1 0.1 0.01 0.001 Seconds 0.0001 1e-05 1e-06 10 100 1000 10000 100000 1000000 Data Length in Bytes Rijndael Twofish GOST Blowfish 3DES Serpent CAST6 xTEA CAST5 p4-3200-gentoo Crypto++ Ciphers: Speed by Data Length 50 45 40 35 -
Applications of Search Techniques to Cryptanalysis and the Construction of Cipher Components. James David Mclaughlin Submitted F
Applications of search techniques to cryptanalysis and the construction of cipher components. James David McLaughlin Submitted for the degree of Doctor of Philosophy (PhD) University of York Department of Computer Science September 2012 2 Abstract In this dissertation, we investigate the ways in which search techniques, and in particular metaheuristic search techniques, can be used in cryptology. We address the design of simple cryptographic components (Boolean functions), before moving on to more complex entities (S-boxes). The emphasis then shifts from the construction of cryptographic arte- facts to the related area of cryptanalysis, in which we first derive non-linear approximations to S-boxes more powerful than the existing linear approximations, and then exploit these in cryptanalytic attacks against the ciphers DES and Serpent. Contents 1 Introduction. 11 1.1 The Structure of this Thesis . 12 2 A brief history of cryptography and cryptanalysis. 14 3 Literature review 20 3.1 Information on various types of block cipher, and a brief description of the Data Encryption Standard. 20 3.1.1 Feistel ciphers . 21 3.1.2 Other types of block cipher . 23 3.1.3 Confusion and diffusion . 24 3.2 Linear cryptanalysis. 26 3.2.1 The attack. 27 3.3 Differential cryptanalysis. 35 3.3.1 The attack. 39 3.3.2 Variants of the differential cryptanalytic attack . 44 3.4 Stream ciphers based on linear feedback shift registers . 48 3.5 A brief introduction to metaheuristics . 52 3.5.1 Hill-climbing . 55 3.5.2 Simulated annealing . 57 3.5.3 Memetic algorithms . 58 3.5.4 Ant algorithms . -
Generic Attacks Against Beyond-Birthday-Bound Macs
Generic Attacks against Beyond-Birthday-Bound MACs Gaëtan Leurent1, Mridul Nandi2, and Ferdinand Sibleyras1 1 Inria, France {gaetan.leurent,ferdinand.sibleyras}@inria.fr 2 Indian Statistical Institute, Kolkata [email protected] Abstract. In this work, we study the security of several recent MAC constructions with provable security beyond the birthday bound. We con- sider block-cipher based constructions with a double-block internal state, such as SUM-ECBC, PMAC+, 3kf9, GCM-SIV2, and some variants (LightMAC+, 1kPMAC+). All these MACs have a security proof up to 22n/3 queries, but there are no known attacks with less than 2n queries. We describe a new cryptanalysis technique for double-block MACs based on finding quadruples of messages with four pairwise collisions in halves of the state. We show how to detect such quadruples in SUM-ECBC, PMAC+, 3kf9, GCM-SIV2 and their variants with O(23n/4) queries, and how to build a forgery attack with the same query complexity. The time com- plexity of these attacks is above 2n, but it shows that the schemes do not reach full security in the information theoretic model. Surprisingly, our attack on LightMAC+ also invalidates a recent security proof by Naito. Moreover, we give a variant of the attack against SUM-ECBC and GCM-SIV2 with time and data complexity O˜(26n/7). As far as we know, this is the first attack with complexity below 2n against a deterministic beyond- birthday-bound secure MAC. As a side result, we also give a birthday attack against 1kf9, a single-key variant of 3kf9 that was withdrawn due to issues with the proof. -
Hash Functions & Macs ECE 646 Lecture 9
ECE 646 Lecture 9 Required Reading W. Stallings, "Cryptography and Network-Security,” Chapter 11 Cryptographic Hash Functions Appendix 11A Mathematical Basis of Birthday Attack Hash functions & MACs Chapter 12 Message Authentication Codes Recommended Reading SHA-3 Project https://csrc.nist.gov/projects/hash-functions/sha-3-project 1 2 Digital Signature Hash function Alice Bob arbitrary length Message Signature Message Signature m message Hash Hash function function hash h Hash value 1 function Hash value yes no Hash value 2 Public key Public key h(m) hash value algorithm algorithm fixed length Alice’s private key Alice’s public key 3 4 1 Vocabulary Hash functions Basic requirements hash function hash value 1. Public description, NO key message digest message digest hash total 2. Compression fingerprint arbitrary length input ® fixed length output imprint 3. Ease of computation cryptographic checksum compressed encoding MDC, Message Digest Code 5 6 Hash functions Hash functions Security requirements Dependence between requirements It is computationally infeasible Given To Find 1. Preimage resistance 2nd preimage resistant y x, such that h(x) = y collision resistant 2. 2nd preimage resistance x’ ¹ x, such that x and y=h(x) h(x’) = h(x) = y 3. Collision resistance x’ ¹ x, such that h(x’) = h(x) 7 8 2 Hash functions Brute force attack against (unkeyed) One-Way Hash Function Given y mi’ One-Way Collision-Resistant i=1..2n Hash Functions Hash Functions 2n messages with the contents required by the forger OWHF CRHF h preimage resistance ? 2nd preimage resistance h(mi’) = y collision resistance n - bits 9 10 Creating multiple versions of Brute force attack against Yuval the required message Collision Resistant Hash Function state thereby borrowed I confirm - that I received r messages r messages acceptable for the signer required by the forger $10,000 Mr.