Hash Functions
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Improved Cryptanalysis of the Reduced Grøstl Compression Function, ECHO Permutation and AES Block Cipher
Improved Cryptanalysis of the Reduced Grøstl Compression Function, ECHO Permutation and AES Block Cipher Florian Mendel1, Thomas Peyrin2, Christian Rechberger1, and Martin Schl¨affer1 1 IAIK, Graz University of Technology, Austria 2 Ingenico, France [email protected],[email protected] Abstract. In this paper, we propose two new ways to mount attacks on the SHA-3 candidates Grøstl, and ECHO, and apply these attacks also to the AES. Our results improve upon and extend the rebound attack. Using the new techniques, we are able to extend the number of rounds in which available degrees of freedom can be used. As a result, we present the first attack on 7 rounds for the Grøstl-256 output transformation3 and improve the semi-free-start collision attack on 6 rounds. Further, we present an improved known-key distinguisher for 7 rounds of the AES block cipher and the internal permutation used in ECHO. Keywords: hash function, block cipher, cryptanalysis, semi-free-start collision, known-key distinguisher 1 Introduction Recently, a new wave of hash function proposals appeared, following a call for submissions to the SHA-3 contest organized by NIST [26]. In order to analyze these proposals, the toolbox which is at the cryptanalysts' disposal needs to be extended. Meet-in-the-middle and differential attacks are commonly used. A recent extension of differential cryptanalysis to hash functions is the rebound attack [22] originally applied to reduced (7.5 rounds) Whirlpool (standardized since 2000 by ISO/IEC 10118-3:2004) and a reduced version (6 rounds) of the SHA-3 candidate Grøstl-256 [14], which both have 10 rounds in total. -
Apunet: Revitalizing GPU As Packet Processing Accelerator
APUNet: Revitalizing GPU as Packet Processing Accelerator Younghwan Go, Muhammad Asim Jamshed, YoungGyoun Moon, Changho Hwang, and KyoungSoo Park School of Electrical Engineering, KAIST GPU-accelerated Networked Systems • Execute same/similar operations on each packet in parallel • High parallelization power • Large memory bandwidth CPU GPU Packet Packet Packet Packet Packet Packet • Improvements shown in number of research works • PacketShader [SIGCOMM’10], SSLShader [NSDI’11], Kargus [CCS’12], NBA [EuroSys’15], MIDeA [CCS’11], DoubleClick [APSys’12], … 2 Source of GPU Benefits • GPU acceleration mainly comes from memory access latency hiding • Memory I/O switch to other thread for continuous execution GPU Quick GPU Thread 1 Thread 2 Context Thread 1 Thread 2 Switch … … … … a = b + c; a = b + c; d =Inactivee * f; Inactive d = e * f; … … … … v = mem[a].val; … v = mem[a].val; … Memory Prefetch in I/O background 3 Memory Access Hiding in CPU vs. GPU • Re-order CPU code to mask memory access (G-Opt)* • Group prefetching, software pipelining Questions: Can CPU code optimization be generalized to all network applications? Which processor is more beneficial in packet processing? *Borrowed from G-Opt slides *Raising the Bar for Using GPUs in Software Packet Processing [NSDI’15] 4 Anuj Kalia, Dong Zhu, Michael Kaminsky, and David G. Anderson Contributions • Demystify processor-level effectiveness on packet processing algorithms • CPU optimization benefits light-weight memory-bound workloads • CPU optimization often does not help large memory -
Compact Implementation of KECCAK SHA3-1024 Hash Algorithm
International Journal of Emerging Engineering Research and Technology Volume 3, Issue 8, August 2015, PP 41-48 ISSN 2349-4395 (Print) & ISSN 2349-4409 (Online) Compact Implementation of KECCAK SHA3-1024 Hash Algorithm Bonagiri Hemanthkumar1, T. Krishnarjuna Rao2, Dr. D. Subba Rao3 1Department of ECE, Siddhartha Institute of Engineering and Technology, Hyderabad, India (PG Scholar) 2Department of ECE, Siddhartha Institute of Engineering and Technology, Hyderabad, India (Associate Professor) 3Department of ECE, Siddhartha Institute of Engineering and Technology, Hyderabad, India (Head of the Department) ABSTRACT Five people with five different approaches has proposed SHA3 algorithm. NIST (National Institute of Standards and Technology) has selected an approach, which was proposed by Keccak. The proposed design is logically optimized for area efficiency by merging Rho, Pi and Chi steps of algorithm into single step, by logically merging these three steps we save 16 % logical resources for overall implementation. It in turn reduced latency and enhanced maximum operating frequency of design, our design shows the best throughput per slice (TPS) ratio, in this paper we are implementing SHA3 1024 variant using Xilinx 13.2 Keywords: theta, rho, pi, chi, iota. INTRODUCTION MD5 is one in a series of message digest algorithms designed by Professor Ronald Rivest of MIT (Rivest, 1992). When analytic work indicated that MD5's predecessor MD4 was likely to be insecure, Rivest designed MD5 in 1991 as a secure replacement. (Hans Dobbertin did indeed later find weaknesses in MD4.)In 1993, Den Boer and Baseliners gave an early, although limited, result of finding a "pseudo-collision" of the MD5 compression function; that is, two different initialization vectors which produce an identical digest. -
Agilio® SSL and SSH Visibility TRANSPARENT SSL/SSH PROXY AS SMARTNIC OR APPLIANCE
PRODUCT BRIEF Agilio® SSL and SSH Visibility TRANSPARENT SSL/SSH PROXY AS SMARTNIC OR APPLIANCE Pervasive Adoption of SSL and TLS SSL has become the dominant stream-oriented encryption protocol and now con- stitutes a significant and growing percentage of the traffic in the enterprise LAN and WAN, as well as throughout service provider networks. It has proven popular as it is easily deployed by software vendors, while offering privacy and integrity protection. The privacy benefits provided by SSL can quickly be overshadowed by the risks it KEY FEATURES brings to enterprises. Network-based threats, such as spam, spyware and viruses Decrypts SSH, SSL 3, - not to mention phishing, identity theft, accidental or intentional leakage of confi- TLS 1.0, 1.1, 1.2 and 1.3 dential information and other forms of cyber crime - have become commonplace. Unmodified attached software Network security appliances, though, are often blind to the payloads of SSL-en- and appliances gain visibility crypted communications and cannot inspect this traffic, leaving a hole in any enter- into SSL traffic prise security architecture. Known key and certificate re- signing modes Existing methods to control SSL include limiting or preventing its use, preventing its use entirely, deploying host-based IPS systems or installing proxy SSL solutions that Offloads and accelerates SSL significantly reduce network performance. processing Delivers traffic to software via Agilio SSL and SSH Visibility Technology kernel netdev, DPDK, PCAP or Netronome’s SSL and SSH Visibility technology enables standard unmodified soft- netmap interfaces ware and appliances to inspect the contents of SSL while not compromising the use Delivers traffic to physical of SSL or reducing performance. -
Hash Functions and Thetitle NIST of Shapresentation-3 Competition
The First 30 Years of Cryptographic Hash Functions and theTitle NIST of SHAPresentation-3 Competition Bart Preneel COSIC/Kath. Univ. Leuven (Belgium) Session ID: CRYP-202 Session Classification: Hash functions decoded Insert presenter logo here on slide master Hash functions X.509 Annex D RIPEMD-160 MDC-2 SHA-256 SHA-3 MD2, MD4, MD5 SHA-512 SHA-1 This is an input to a crypto- graphic hash function. The input is a very long string, that is reduced by the hash function to a string of fixed length. There are 1A3FD4128A198FB3CA345932 additional security conditions: it h should be very hard to find an input hashing to a given value (a preimage) or to find two colliding inputs (a collision). Hash function history 101 DES RSA 1980 single block ad hoc length schemes HARDWARE MD2 MD4 1990 SNEFRU double MD5 block security SHA-1 length reduction for RIPEMD-160 factoring, SHA-2 2000 AES permu- DLOG, lattices Whirlpool SOFTWARE tations SHA-3 2010 Applications • digital signatures • data authentication • protection of passwords • confirmation of knowledge/commitment • micropayments • pseudo-random string generation/key derivation • construction of MAC algorithms, stream ciphers, block ciphers,… Agenda Definitions Iterations (modes) Compression functions SHA-{0,1,2,3} Bits and bytes 5 Hash function flavors cryptographic hash function this talk MAC MDC OWHF CRHF UOWHF (TCR) Security requirements (n-bit result) preimage 2nd preimage collision ? x ? ? ? h h h h h h(x) h(x) = h(x‘) h(x) = h(x‘) 2n 2n 2n/2 Informal definitions (1) • no secret parameters -
Hash Functions
11 Hash Functions Suppose you share a huge le with a friend, but you are not sure whether you both have the same version of the le. You could send your version of the le to your friend and they could compare to their version. Is there any way to check that involves less communication than this? Let’s call your version of the le x (a string) and your friend’s version y. The goal is to determine whether x = y. A natural approach is to agree on some deterministic function H, compute H¹xº, and send it to your friend. Your friend can compute H¹yº and, since H is deterministic, compare the result to your H¹xº. In order for this method to be fool-proof, we need H to have the property that dierent inputs always map to dierent outputs — in other words, H must be injective (1-to-1). Unfortunately, if H is injective and H : f0; 1gin ! f0; 1gout is injective, then out > in. This means that sending H¹xº is no better/shorter than sending x itself! Let us call a pair ¹x;yº a collision in H if x , y and H¹xº = H¹yº. An injective function has no collisions. One common theme in cryptography is that you don’t always need something to be impossible; it’s often enough for that thing to be just highly unlikely. Instead of saying that H should have no collisions, what if we just say that collisions should be hard (for polynomial-time algorithms) to nd? An H with this property will probably be good enough for anything we care about. -
Authenticated Encryption
Authen'cated Encryp'on Andrey Bogdanov Technical University of Denmark June 2, 2014 Scope • Main focus on modes of operaon for block ciphers • Permutaon-based designs briefly men'oned Outline • Block ciphers • Basic modes of operaon • AE and AEAD • Nonce-based AE modes and features • Nonce-based AE: Implementaon proper'es • Nonce-free AE modes and features • Nonce-free AE: Implementaon proper'es • Permutaon-based AE Outline • Block ciphers • Basic modes of operaon • AE and AEAD • Nonce-based AE modes and features • Nonce-based AE: Implementaon proper'es • Nonce-free AE modes and features • Nonce-free AE: Implementaon proper'es • Permutaon-based AE Block ciphers plaintext ciphertext block cipher n bits n bits key k bits Block cipher 2n! A block cipher with n-bit block and k-bit key is a subset of 2k permutaons among all 2n! permuta9ons on n bits. Subset: 2k Some standard block ciphers plaintext ciphertext f f … f n bits 1 2 r n bits AES PRESENT Visualizaon of a round transform Why block ciphers? • Most basic security primi've in nearly all security solu'ons, e.g. used for construc'ng – stream ciphers, – hash func'ons, – message authen'caon codes, – authencated encrypon algorithms, – entropy extractors, … • Probably the best understood cryptographic primi'ves • U.S. symmetric-key encryp'on standards and recommendaons have block ciphers at their core: DES, AES Modes of operaon • The block cipher itself only encrypts one block of data – Standard and efficient block ciphers such as AES • To encrypt data that is not exactly one block – Switch a -
Tocubehash, Grøstl, Lane, Toshabal and Spectral Hash
FPGA Implementations of SHA-3 Candidates: CubeHash, Grøstl, Lane, Shabal and Spectral Hash Brian Baldwin, Andrew Byrne, Mark Hamilton, Neil Hanley, Robert P. McEvoy, Weibo Pan and William P. Marnane Claude Shannon Institute for Discrete Mathematics, Coding and Cryptography & Department of Electrical & Electronic Engineering, University College Cork, Ireland. Hash Functions The SHA-3 Contest Hash Function Implementations Results Conclusions Overview Hash Function Description Introduction Background Operation UCC Cryptography Group, 2009 The Claude Shannon Workshop On Coding and Cryptography Hash Functions The SHA-3 Contest Hash Function Implementations Results Conclusions Overview Hash Function Description Introduction Background Operation The SHA-3 Contest UCC Cryptography Group, 2009 The Claude Shannon Workshop On Coding and Cryptography Hash Functions The SHA-3 Contest Hash Function Implementations Results Conclusions Overview Hash Function Description Introduction Background Operation The SHA-3 Contest Overview of the Hash Function Architectures UCC Cryptography Group, 2009 The Claude Shannon Workshop On Coding and Cryptography Hash Functions The SHA-3 Contest Hash Function Implementations Results Conclusions Overview Hash Function Description Introduction Background Operation The SHA-3 Contest Overview of the Hash Function Architectures Hash Function Implementations CubeHash Grøstl Lane Shabal Spectral Hash UCC Cryptography Group, 2009 The Claude Shannon Workshop On Coding and Cryptography Hash Functions The SHA-3 Contest Hash Function -
The First Cryptographic Hash Workshop
Workshop Report The First Cryptographic Hash Workshop Gaithersburg, MD Oct. 31-Nov. 1, 2005 Report prepared by Shu-jen Chang and Morris Dworkin Information Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 Available online: http://csrc.nist.gov/groups/ST/hash/documents/HashWshop_2005_Report.pdf 1. Introduction On Oct. 31-Nov. 1, 2005, 180 members of the global cryptographic community gathered in Gaithersburg, MD to attend the first Cryptographic Hash Workshop. The workshop was organized in response to a recent attack on the NIST-approved Secure Hash Algorithm SHA-1. The purpose of the workshop was to discuss this attack, assess the status of other NIST-approved hash algorithms, and discuss possible near-and long-term options. 2. Workshop Program The workshop program consisted of two days of presentations of papers that were submitted to the workshop and panel discussion sessions that NIST organized. The main topics for the discussions included the SHA-1 and SHA-2 hash functions, future research of hash functions, and NIST’s strategy. The program is available at http://csrc.nist.gov/groups/ST/hash/first_workshop.html. This report only briefly summarizes the presentations, because the above web site for the program includes links to the speakers' slides and papers. The main ideas of the discussion sessions, however, are described in considerable detail; in fact, the panelists and attendees are often paraphrased very closely, to minimize misinterpretation. Their statements are not necessarily presented in the order that they occurred, in order to organize them according to NIST's questions for each session. 3. -
Improved Cryptanalysis of the Reduced Grøstl Compression Function, ECHO Permutation and AES Block Cipher
Improved Cryptanalysis of the Reduced Grøstl Compression Function, ECHO Permutation and AES Block Cipher Florian Mendel1,ThomasPeyrin2,ChristianRechberger1, and Martin Schl¨affer1 1 IAIK, Graz University of Technology, Austria 2 Ingenico, France [email protected], [email protected] Abstract. In this paper, we propose two new ways to mount attacks on the SHA-3 candidates Grøstl,andECHO, and apply these attacks also to the AES. Our results improve upon and extend the rebound attack. Using the new techniques, we are able to extend the number of rounds in which available degrees of freedom can be used. As a result, we present the first attack on 7 rounds for the Grøstl-256 output transformation1 and improve the semi-free-start collision attack on 6 rounds. Further, we present an improved known-key distinguisher for 7 rounds of the AES block cipher and the internal permutation used in ECHO. Keywords: hash function, block cipher, cryptanalysis, semi-free-start collision, known-key distinguisher. 1 Introduction Recently, a new wave of hash function proposals appeared, following a call for submissions to the SHA-3 contest organized by NIST [26]. In order to analyze these proposals, the toolbox which is at the cryptanalysts’ disposal needs to be extended. Meet-in-the-middle and differential attacks are commonly used. A recent extension of differential cryptanalysis to hash functions is the rebound attack [22] originally applied to reduced (7.5 rounds) Whirlpool (standardized since 2000 by ISO/IEC 10118-3:2004) and a reduced version (6 rounds) of the SHA-3 candidate Grøstl-256 [14], which both have 10 rounds in total. -
Finding Bugs in Cryptographic Hash Function Implementations Nicky Mouha, Mohammad S Raunak, D
1 Finding Bugs in Cryptographic Hash Function Implementations Nicky Mouha, Mohammad S Raunak, D. Richard Kuhn, and Raghu Kacker Abstract—Cryptographic hash functions are security-critical on the SHA-2 family, these hash functions are in the same algorithms with many practical applications, notably in digital general family, and could potentially be attacked with similar signatures. Developing an approach to test them can be par- techniques. ticularly diffcult, and bugs can remain unnoticed for many years. We revisit the NIST hash function competition, which was In 2007, the National Institute of Standards and Technology used to develop the SHA-3 standard, and apply a new testing (NIST) released a Call for Submissions [4] to develop the new strategy to all available reference implementations. Motivated SHA-3 standard through a public competition. The intention by the cryptographic properties that a hash function should was to specify an unclassifed, publicly disclosed algorithm, to satisfy, we develop four tests. The Bit-Contribution Test checks be available worldwide without royalties or other intellectual if changes in the message affect the hash value, and the Bit- Exclusion Test checks that changes beyond the last message bit property restrictions. To allow the direct substitution of the leave the hash value unchanged. We develop the Update Test SHA-2 family of algorithms, the SHA-3 submissions were to verify that messages are processed correctly in chunks, and required to provide the same four message digest lengths. then use combinatorial testing methods to reduce the test set size Chosen through a rigorous open process that spanned eight by several orders of magnitude while retaining the same fault- years, SHA-3 became the frst hash function standard that detection capability. -
Grøstl – a SHA-3 Candidate
Cryptographic hash functions NIST SHA-3 Competition Grøstl Grøstl – a SHA-3 candidate Krystian Matusiewicz Wroclaw University of Technology CECC 2010, June 12, 2010 Krystian Matusiewicz Grøstl – a SHA-3 candidate 1 / 26 Cryptographic hash functions NIST SHA-3 Competition Grøstl Talk outline ◮ Cryptographic hash functions ◮ NIST SHA-3 Competition ◮ Grøstl Krystian Matusiewicz Grøstl – a SHA-3 candidate 2 / 26 Cryptographic hash functions NIST SHA-3 Competition Grøstl Cryptographic hash functions Krystian Matusiewicz Grøstl – a SHA-3 candidate 3 / 26 Cryptographic hash functions NIST SHA-3 Competition Grøstl Cryptographic hash functions: why? ◮ We want to have a short, fixed length “fingerprint” of any piece of data ◮ Different fingerprints – certainly different data ◮ Identical fingerprints – most likely the same data ◮ No one can get any information about the data from the fingerprint Krystian Matusiewicz Grøstl – a SHA-3 candidate 4 / 26 Cryptographic hash functions NIST SHA-3 Competition Grøstl Random Oracle Construction: ◮ Box with memory ◮ On a new query: pick randomly and uniformly the answer, remember it and return the result ◮ On a repeating query, repeat the answer (function) Krystian Matusiewicz Grøstl – a SHA-3 candidate 5 / 26 Cryptographic hash functions NIST SHA-3 Competition Grøstl Random Oracle Construction: ◮ Box with memory ◮ On a new query: pick randomly and uniformly the answer, remember it and return the result ◮ On a repeating query, repeat the answer (function) Properties: ◮ No information about the data ◮ To find a preimage: