Dissertation Docteur De L'université Du Luxembourg
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Argon and Argon2
Argon and Argon2 Designers: Alex Biryukov, Daniel Dinu, and Dmitry Khovratovich University of Luxembourg, Luxembourg [email protected], [email protected], [email protected] https://www.cryptolux.org/index.php/Password https://github.com/khovratovich/Argon https://github.com/khovratovich/Argon2 Version 1.1 of Argon Version 1.0 of Argon2 31th January, 2015 Contents 1 Introduction 3 2 Argon 5 2.1 Specification . 5 2.1.1 Input . 5 2.1.2 SubGroups . 6 2.1.3 ShuffleSlices . 7 2.2 Recommended parameters . 8 2.3 Security claims . 8 2.4 Features . 9 2.4.1 Main features . 9 2.4.2 Server relief . 10 2.4.3 Client-independent update . 10 2.4.4 Possible future extensions . 10 2.5 Security analysis . 10 2.5.1 Avalanche properties . 10 2.5.2 Invariants . 11 2.5.3 Collision and preimage attacks . 11 2.5.4 Tradeoff attacks . 11 2.6 Design rationale . 14 2.6.1 SubGroups . 14 2.6.2 ShuffleSlices . 16 2.6.3 Permutation ...................................... 16 2.6.4 No weakness,F no patents . 16 2.7 Tweaks . 17 2.8 Efficiency analysis . 17 2.8.1 Modern x86/x64 architecture . 17 2.8.2 Older CPU . 17 2.8.3 Other architectures . 17 3 Argon2 19 3.1 Specification . 19 3.1.1 Inputs . 19 3.1.2 Operation . 20 3.1.3 Indexing . 20 3.1.4 Compression function G ................................. 21 3.2 Features . 22 3.2.1 Available features . 22 3.2.2 Server relief . 23 3.2.3 Client-independent update . -
Deanonymisation of Clients in Bitcoin P2P Network
Deanonymisation of clients in Bitcoin P2P network Alex Biryukov Dmitry Khovratovich Ivan Pustogarov University of Luxembourg University of Luxembourg University of Luxembourg [email protected] [email protected] [email protected] Abstract about 100,000 nowadays. The vast majority of these peers Bitcoin is a digital currency which relies on a distributed (we call them clients), about 90%, are located behind NAT set of miners to mint coins and on a peer-to-peer network and do not allow any incoming connections, whereas they to broadcast transactions. The identities of Bitcoin users choose 8 outgoing connections to servers (Bitcoin peers with are hidden behind pseudonyms (public keys) which are rec- public IP). ommended to be changed frequently in order to increase In a Bitcoin transaction, the address of money sender(s) transaction unlinkability. or receiver(s) is a hash of his public key. We call such We present an efficient method to deanonymize Bitcoin address a pseudonym to avoid confusion with the IP ad- users, which allows to link user pseudonyms to the IP ad- dress of the host where transactions are generated, and the dresses where the transactions are generated. Our tech- latter will be called just address throughout the text. In niques work for the most common and the most challenging the current Bitcoin protocol the entire transaction history scenario when users are behind NATs or firewalls of their is publicly available so anyone can see how Bitcoins travel ISPs. They allow to link transactions of a user behind a from one pseudonym to another and potentially link differ- NAT and to distinguish connections and transactions of dif- ent pseudonyms of the same user together. -
Bicliques for Preimages: Attacks on Skein-512 and the SHA-2 Family
Bicliques for Preimages: Attacks on Skein-512 and the SHA-2 family Dmitry Khovratovich1 and Christian Rechberger2 and Alexandra Savelieva3 1Microsoft Research Redmond, USA 2DTU MAT, Denmark 3National Research University Higher School of Economics, Russia Abstract. We present the new concept of biclique as a tool for preimage attacks, which employs many powerful techniques from differential cryptanalysis of block ciphers and hash functions. The new tool has proved to be widely applicable by inspiring many authors to publish new re- sults of the full versions of AES, KASUMI, IDEA, and Square. In this paper, we demonstrate how our concept results in the first cryptanalysis of the Skein hash function, and describe an attack on the SHA-2 hash function with more rounds than before. Keywords: SHA-2, SHA-256, SHA-512, Skein, SHA-3, hash function, meet-in-the-middle attack, splice-and-cut, preimage attack, initial structure, biclique. 1 Introduction The last years saw an exciting progress in preimage attacks on hash functions. In contrast to collision search [29, 26], where differential cryptanalysis has been in use since 90s, there had been no similarly powerful tool for preimages. The situation changed dramatically in 2008, when the so-called splice-and-cut framework has been applied to MD4 and MD5 [2, 24], and later to SHA-0/1/2 [1, 3], Tiger [10], and other primitives. Despite amazing results on MD5, the applications to SHA-x primitives seemed to be limited by the internal properties of the message schedule procedures. The only promising element, the so-called initial structure tool, remained very informal and complicated. -
Harden Zero Knowledge Password Proofs Against Offline Dictionary
Harden Zero Knowledge Password Proofs Against Offline Dictionary Attacks Gijs Van Laer Rono Dasgupta Aditya Patil [email protected] [email protected] [email protected] Matthew Green [email protected] December 12, 2016 Abstract Traditional authentication systems offer ease of use but the security they provide often proves to be inadequate. Hackers use means to gain access to company servers and steal entire databases of password hashes. These hashes are then subject to offline dictionary attacks resulting in the disclosure of millions of passwords. Such password breaches have become commonplace and have caused several major companies to face major losses. Password reuse is a common practice among users and a password breach disclosing a single password on a particular service could result in a user also losing access to their other accounts. Solutions such as multi-factor authentication add some level of security but do not completely solve the problem. There is a need to move towards stronger authentication schemes that do not compromise on ease of use, both for the user and the service provider. In this paper, we propose a novel authentication protocol that is proven hard against offline dictionary attacks. Our protocol implements a combination of a Zero Knowledge Password Proof and a sequentially memory hard hash function. In a concrete instan- tiation of the protocol, we use Schnorr's Zero Knowledge Password Proof combined with the Fiat-Shamir Heuristic for the Zero Knowledge Password Proof and scrypt for the sequentially memory hard hash function. We also describe a library implementing our protocol that we have developed along with an example web application that uses the library. -
NISTIR 7620 Status Report on the First Round of the SHA-3
NISTIR 7620 Status Report on the First Round of the SHA-3 Cryptographic Hash Algorithm Competition Andrew Regenscheid Ray Perlner Shu-jen Chang John Kelsey Mridul Nandi Souradyuti Paul NISTIR 7620 Status Report on the First Round of the SHA-3 Cryptographic Hash Algorithm Competition Andrew Regenscheid Ray Perlner Shu-jen Chang John Kelsey Mridul Nandi Souradyuti Paul Information Technology Laboratory National Institute of Standards and Technology Gaithersburg, MD 20899-8930 September 2009 U.S. Department of Commerce Gary Locke, Secretary National Institute of Standards and Technology Patrick D. Gallagher, Deputy Director NISTIR 7620: Status Report on the First Round of the SHA-3 Cryptographic Hash Algorithm Competition Abstract The National Institute of Standards and Technology is in the process of selecting a new cryptographic hash algorithm through a public competition. The new hash algorithm will be referred to as “SHA-3” and will complement the SHA-2 hash algorithms currently specified in FIPS 180-3, Secure Hash Standard. In October, 2008, 64 candidate algorithms were submitted to NIST for consideration. Among these, 51 met the minimum acceptance criteria and were accepted as First-Round Candidates on Dec. 10, 2008, marking the beginning of the First Round of the SHA-3 cryptographic hash algorithm competition. This report describes the evaluation criteria and selection process, based on public feedback and internal review of the first-round candidates, and summarizes the 14 candidate algorithms announced on July 24, 2009 for moving forward to the second round of the competition. The 14 Second-Round Candidates are BLAKE, BLUE MIDNIGHT WISH, CubeHash, ECHO, Fugue, Grøstl, Hamsi, JH, Keccak, Luffa, Shabal, SHAvite-3, SIMD, and Skein. -
Re-Visiting HAIFA and Why You Should Visit Too
Merkle-Damg˚ard HAIFA New Results Summary Re-Visiting HAIFA and why you should visit too Orr Dunkelman D´epartement d’Informatique Ecole´ Normale sup´erieure and France Telecom Chaire 3rd of June 2008 Joint work with Eli Biham, Charles Bouillaguet, Pierre-Alain Fouque, S´ebastian Zimmer. Orr Dunkelman Re-Visiting HAIFA and why you should visit too 1/ 42 Merkle-Damg˚ard HAIFA New Results Summary Outline 1 Iterative Hashing — The Merkle Damg˚ard Construction The Merkle-Damg˚ard Construction Generic Attacks on the Merkle-Damg˚ard Construction Possible Conclusions 2 HAsh Iterative FrAmework The HAIFA Construction Dealing with Fix-Points Variable Hash Size Salts 3 New Results on HAIFA Implementing Other Suggested Modes in HAIFA On the Security of HAIFA 4 Summary Orr Dunkelman Re-Visiting HAIFA and why you should visit too 2/ 42 Merkle-Damg˚ard HAIFA New Results Summary MD Generic Attacks Conclusions Outline 1 Iterative Hashing — The Merkle Damg˚ard Construction The Merkle-Damg˚ard Construction Generic Attacks on the Merkle-Damg˚ard Construction Possible Conclusions 2 HAsh Iterative FrAmework The HAIFA Construction Dealing with Fix-Points Variable Hash Size Salts 3 New Results on HAIFA Implementing Other Suggested Modes in HAIFA On the Security of HAIFA 4 Summary Orr Dunkelman Re-Visiting HAIFA and why you should visit too 3/ 42 Merkle-Damg˚ard HAIFA New Results Summary MD Generic Attacks Conclusions The Merkle-Damg˚ard Construction ◮ Presented by Merkle and Damg˚ard independently as an answer to the following problem: ◮ Given a compression function f : {0, 1}mc × {0, 1}n → {0, 1}mc , how would you ∗ m generate a hash function Hf : {0, 1} → {0, 1} . -
Biclique Cryptanalysis of Full Round AES with Reduced Data Complexity
Biclique Cryptanalysis of Full Round AES with Reduced Data Complexity Donghoon Chang, Mohona Ghosh, Somitra Sanadhya Indraprastha Institute of Information Technology donghoon, mohonag,[email protected] Abstract. Biclique cryptanalysis was proposed by Bogdanov et al. in Asiacrypt 2011 as a new tool for cryptanalysis of block ciphers. A major hurdle in carrying out biclique cryptanalysis is that it has a very high query complexity (of the order of 288 for AES-128, 280 for AES-192 and 240 for AES-256). This naturally puts a big question mark over the practical feasibility of implementing biclique attack in real world. In this work, we re-evaluate the security of full round AES against biclique cryptanalysis. We describe an alternate biclique construction with signicantly reduced query complexity (of the order of 224 for AES-128, 232 for AES-192 and 28 for AES-256) at the expense of a slightly increased computational cost. In our approach, we use independent biclique technique to launch a chosen ciphertext attack against AES. Keywords: AES, block ciphers, cryptanalysis, biclique, meet-in-the middle, key recovery. 1 Introduction AES (Advanced Encryption Standard), standardized by the US NIST in October 2000, has been accepted and adopted worldwide thereafter. It remains the most favored cryptographic scheme in both software and hardware applications. Despite the design having been subjected to tremendous scrutiny in the past 12 years, it has remained remarkably immune to all cryptanalytic attacks of practical signicance. Single key recovery attacks such as multiset attack [1], square attack [1], boomerang attack [2, 3], impossible dierentials [4, 5], algebraic attack [6, 7] etc. -
Preimage Attacks on Reduced-Round GOST and Grøstl-256 and Studies on Several Truncation Patterns for AES-Like Compression Functions (Full Version)?
Improved (Pseudo) Preimage Attacks on Reduced-Round GOST and Grøstl-256 and Studies on Several Truncation Patterns for AES-like Compression Functions (Full Version)? Bingke Ma1;2;3, Bao Li1;2, Ronglin Hao1;2;4, and Xiaoqian Li1;2;3 1State Key Laboratory of Information Security, Institute of Information Engineering, Chinese Academy of Sciences, Beijing, 100093, China 2Data Assurance and Communication Security Research Center, Chinese Academy of Sciences, Beijing, 100093, China fbkma,lb,[email protected] 3University of Chinese Academy of Sciences, Beijing, China 4Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, 230027, China [email protected] Abstract. In this paper, we present improved preimage attacks on the reduced-round GOST hash function family, which serves as the new Russian hash standard, with the aid of techniques such as the rebound attack, the Meet-in-the-Middle preimage attack and the multicollisions. Firstly, the preimage attack on 5-round GOST-256 is proposed which is the first preimage attack for GOST-256 at the hash function level. Then we extend the (previous) attacks on 5-round GOST-256 and 6-round GOST-512 to 6.5 and 7.5 rounds respectively by exploiting the involution property of the GOST transposition operation. Secondly, inspired by the preimage attack on GOST-256, we also study the impacts of four representa- tive truncation patterns on the resistance of the Meet-in-the-Middle preimage attack against AES-like compression functions, and propose two stronger truncation patterns which make it more difficult to launch this type of attack. -
Performance Analysis of Cryptographic Hash Functions Suitable for Use in Blockchain
I. J. Computer Network and Information Security, 2021, 2, 1-15 Published Online April 2021 in MECS (http://www.mecs-press.org/) DOI: 10.5815/ijcnis.2021.02.01 Performance Analysis of Cryptographic Hash Functions Suitable for Use in Blockchain Alexandr Kuznetsov1 , Inna Oleshko2, Vladyslav Tymchenko3, Konstantin Lisitsky4, Mariia Rodinko5 and Andrii Kolhatin6 1,3,4,5,6 V. N. Karazin Kharkiv National University, Svobody sq., 4, Kharkiv, 61022, Ukraine E-mail: [email protected], [email protected], [email protected], [email protected], [email protected] 2 Kharkiv National University of Radio Electronics, Nauky Ave. 14, Kharkiv, 61166, Ukraine E-mail: [email protected] Received: 30 June 2020; Accepted: 21 October 2020; Published: 08 April 2021 Abstract: A blockchain, or in other words a chain of transaction blocks, is a distributed database that maintains an ordered chain of blocks that reliably connect the information contained in them. Copies of chain blocks are usually stored on multiple computers and synchronized in accordance with the rules of building a chain of blocks, which provides secure and change-resistant storage of information. To build linked lists of blocks hashing is used. Hashing is a special cryptographic primitive that provides one-way, resistance to collisions and search for prototypes computation of hash value (hash or message digest). In this paper a comparative analysis of the performance of hashing algorithms that can be used in modern decentralized blockchain networks are conducted. Specifically, the hash performance on different desktop systems, the number of cycles per byte (Cycles/byte), the amount of hashed message per second (MB/s) and the hash rate (KHash/s) are investigated. -
Speeding up Collision Search for Byte-Oriented Hash Functions
Speeding up Collision Search for Byte-Oriented Hash Functions View metadata, citation and similar papers at core.ac.uk brought to you by CORE Dmitry Khovratovich, Alex Biryukov,provided and by Ivica Open Repository Nikolic and Bibliography - Luxembourg University of Luxembourg {dmitry.khovratovich,alex.biryukov,ivica.nikolic}@uni.lu Abstract. We describe a new tool for the search of collisions for hash functions. The tool is applicable when an attack is based on a differential trail, whose probability determines the complexity of the attack. Using the linear algebra methods we show how to organize the search so that many (in some cases — all) trail conditions are always satisfied thus significantly reducing the number of trials and the overall complexity. The method is illustrated with the collision and second preimage at- tacks on the compression functions based on Rijndael. We show that slow diffusion in the Rijndael (and AES) key schedule allows to run an attack on a version with a 13-round compression function, and the S-boxes do not prevent the attack. We finally propose how to modify the key sched- ule to resist the attack and provide lower bounds on the complexity of the generic differential attacks for our modification. 1 Introduction Bit-oriented hash functions like MD5 [17] and SHA [10] have drawn much at- tention since the early 1990s being the de-facto standard in the industry. Re- cent cryptanalytic efforts and the appearance of real collisions for underlying compression functions [19,18,4,13] motivated researchers to develop new fast primitives. Several designs were presented last years (LASH [2], Grindahl [12], RadioGatun [3], LAKE [1]) but many have already been broken [14,15,6]. -
Attacks on and Advances in Secure Hash Algorithms
IAENG International Journal of Computer Science, 43:3, IJCS_43_3_08 ______________________________________________________________________________________ Attacks on and Advances in Secure Hash Algorithms Neha Kishore, Member IAENG, and Bhanu Kapoor service but is a collection of various services. These services Abstract— In today’s information-based society, encryption include: authentication, access control, data confidentiality, along with the techniques for authentication and integrity are non-repudiation, and data integrity[1]. A system has to key to the security of information. Cryptographic hashing ensure one or more of these depending upon the security algorithms, such as the Secure Hashing Algorithms (SHA), are an integral part of the solution to the information security requirements for a particular system. For example, in problem. This paper presents the state of art hashing addition to the encryption of the data, we may also need algorithms including the security challenges for these hashing authentication and data integrity checks for most of the algorithms. It also covers the latest research on parallel situations in the dynamic context [2]. The development of implementations of these cryptographic algorithms. We present cryptographic hashing algorithms, to ensure authentication an analysis of serial and parallel implementations of these and data integrity services as part of ensuring information algorithms, both in hardware and in software, including an analysis of the performance and the level of protection offered security, has been an active area of research. against attacks on the algorithms. For ensuring data integrity, SHA-1[1] and MD5[1] are the most common hashing algorithms being used in various Index Terms—Cryptographic Hash Function, Parallel types of applications. -
Improved Generic Attacks Against Hash-Based Macs and HAIFA⋆
Improved Generic Attacks Against Hash-based MACs and HAIFA? Itai Dinur1 and Ga¨etanLeurent2 1 D´epartement d'Informatique, Ecole´ Normale Sup´erieure,Paris, France [email protected] 2 Inria, EPI SECRET, France [email protected] Abstract. The security of HMAC (and more general hash-based MACs) against state-recovery and universal forgery attacks was very recently shown to be suboptimal, following a series of surprising results by Leurent et al. and Peyrin et al.. These results have shown that such powerful attacks require much less than 2` computations, contradicting the common belief (where ` denotes the internal state size). In this work, we revisit and extend these results, with a focus on properties of concrete hash functions such as a limited message length, and special iteration modes. We begin by devising the first state-recovery attack on HMAC with a HAIFA hash function (using a block counter in every compression function call), with complexity 24`=5. Then, we describe improved trade- offs between the message length and the complexity of a state-recovery attack on HMAC. Consequently, we obtain improved attacks on several HMAC constructions used in practice, in which the hash functions limit the maximal message length (e.g., SHA-1 and SHA-2). Finally, we present the first universal forgery attacks, which can be applied with short message queries to the MAC oracle. In particular, we devise the first universal forgery attacks applicable to SHA-1 and SHA-2. Keywords: Hash functions, MAC, HMAC, Merkle-Damg˚ard,HAIFA, state-recovery attack, universal forgery attack, GOST, Streebog, SHA family.