4,363 research outputs found
Performance Analysis of Modified SHA-3
No full textAbstractSecurity services have become an inseparable feature of almost all digital transactions. A crucial module of these scheme isintegrity, which is performed using a cryptographic hash function. Secure Hash Algorithm can be an efficient hashing technique.SHA-3 is the most recent and efficient Secure Hash Algorithm. Keccak has been chosen as the official algorithm for SHA-3 in2012. In this paper we propose a modification on the design of Secure Hash Algorithm (SHA-3) on Xilinx Field ProgrammableGate Array (FPGA) device. In order to provide reliable architecture for this algorithm, a concurrent error tolerant scheme forSHA-3 is used. A system based on the combination of SHA-3 and error tolerant scheme is also described. Simulation resultsshows, an efficiency in area and delay of SHA-3 designs
Dynamic SHA-2
No full textIn this paper I describe the construction of Dynamic SHA-2 family of cryptographic hash functions. They are built with design components from the SHA-2 family, but I use the bits in message as parameters of function G, R and ROTR operation in the new hash functionh. It enabled us to achieve a novel design principle: When message is changed, the calculation will be different. It make the system can resistant against all extant attacks
116. Gion-sha
No full textIwao Seiichi, Sakamato Tarō, Hōgetsu Keigo, Yoshikawa Itsuji, Akiyama Terukazu, Iyanaga Teizō, Iyanaga Shōkichi, Matsubara Hideichi, Kanazawa Shizue. 116. Gion-sha. In: Dictionnaire historique du Japon, volume 6, 1981. Lettre G. pp. 63-64
116. Gion-sha
No full textIwao Seiichi, Sakamato Tarō, Hōgetsu Keigo, Yoshikawa Itsuji, Akiyama Terukazu, Iyanaga Teizō, Iyanaga Shōkichi, Matsubara Hideichi, Kanazawa Shizue. 116. Gion-sha. In: Dictionnaire historique du Japon, volume 6, 1981. Lettre G. pp. 63-64
Security and usability of standard has hfunctions, in particular MD-5, SHA-1 and SHA-2
No full textTitle: Security and usability of standard hash functions, in particular MD-5, SHA-1 and SHA-2 Author: Galaczová Barbora Department: Department of Algebra Supervisor: Doc. RNDr. Tůma Jiří, DrSc., Department of Algebra Consultant: Ing. Budiš Petr, Ph.D. Abstract: In the present work we try to digestedly describe standard hash functions, in particular MD-5, SHA-1 and SHA-2. We describe resume of existing attacks on these hash functions. We closely focused on MD-5 collision attacks, because the other hash function collision attacks result from these. Next we describe posibilities of practical usage of hash function collisions, in particular into the qualified certificates area and possible threats. At the end to the present work we describe new hash functions, which could replace current hash functions. This work also contains software to calculate MD-5 hash and search it`s collisions. The software is based on method invented by Czech cryptoanalytist Vlastimil Klíma. Keywords: hash function, collision, qualified certificate, security
Security Reductions of the Second Round SHA-3 Candidates
No full text© 2011, Springer-Verlag Berlin Heidelberg. In 2007, the US National Institute for Standards and Technology announced a call for the design of a new cryptographic hash algorithm in response to vulnerabilities identified in existing hash functions, such as MD5 and SHA-1. NIST received many submissions, 51 of which got accepted to the first round. At present, 14 candidates are left in the second round. An important criterion in the selection process is the SHA-3 hash function security and more concretely, the possible security reductions of the hash function to the security of its underlying building blocks. While some of the candidates are supported with firm security reductions, for most of the schemes these results are still incomplete. In this paper, we compare the state of the art provable security reductions of the second round SHA-3 candidates. Surprisingly, we derive some security bounds from the literature, which the hash function designers seem to be unaware of. Additionally, we generalize the well-known proof of collision resistance preservation, such that all SHA-3 candidates with a suffix-free padding are covered.sponsorship: This work has been funded in part by the IAP Program P6/26 BCRYPT of the Belgian State (Belgian Science Policy), and in part by the European Commission through the ICT program under contract ICT-2007- 216676 ECRYPT II. The first author is supported by a Ph.D. Fellowship from the Flemish Research Foundation (FWO-Vlaanderen). The second author is supported by a Ph.D. Fellowship from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). (IAP of the Belgian State (Belgian Science Policy|P6/26 BCRYPT, European Commission through the ICT program|ICT-2007- 216676, Flemish Research Foundation (FWO-Vlaanderen), Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen))status: Publishe
Further studies on the pharmacological profile of the neuropeptide S receptor antagonist SHA 68.
No full textNeuropeptide S (NPS) regulates various biological functions by selectively activating the NPS receptor (NPSR). Previous studies demonstrated that the non-peptide molecule SHA 68 acts as a selective NPSR antagonist. In the present study the pharmacological profile of SHA 68 has been further investigated in vitro and in vivo. In cells expressing the mouse NPSR SHA 68 was inactive per se up to 10microM while it antagonized NPS-stimulated calcium mobilization in a competitive manner showing a pA(2) value of 8.06. In the 10-50mg/kg range of doses, SHA 68 counteracted the stimulant effects elicited by NPS, but not those of caffeine, in mouse locomotor activity experiments. In the mouse righting reflex assay SHA 68 fully prevented the arousal-promoting action of the peptide. The anxiolytic-like effects of NPS were slightly reduced by SHA 68 in the mouse open field, fully prevented in the rat elevated plus maze and partially antagonized in the rat defensive burying paradigm. Finally, SHA 68 was found poorly active in antagonizing the NPS inhibitory effect on palatable food intake in rats. In all assays SHA 68 did not produce any effect per se. In conclusion, the present study demonstrated that SHA 68 behaves as a selective NPSR antagonist that can be used to characterize the in vivo actions of NPS. However the usefulness of this research tool is limited by its poor pharmacokinetic properties
Cryptanalysis of Dynamic SHA(2)
No full textIn this paper, we analyze the hash functions Dynamic SHA and Dynamic SHA2, which have been selected as first round candidates in the NIST hash function competition. These hash functions rely heavily on data-dependent rotations, similar to certain block ciphers, e.g., RC5. Our analysis suggests that in the case of hash functions, where the attacker has more control over the rotations, this approach is less favorable than in block ciphers. We present practical, or close to practical, collision attacks on both Dynamic SHA and Dynamic SHA2. Moreover, we present a preimage attack on Dynamic SHA that is faster than exhaustive search. © 2009 Springer-Verlag Berlin Heidelberg.sponsorship: Supported by the Swiss National Science Foundation, project no. 113329. This author was supported by the France Telecom chaire. F.W.O. Research Assistant, Fund for Scientific Research Flander s (Belgium) (Swiss National Science Foundation|113329, France Telecom chaire, Scientific Research)status: Publishe
Design & Characterization of SHA 3- 256 Bit IP Core
No full textAbstractIn the era of internet and computer networking the need for security have increased rapidly. Various crypto algorithms are used for secured data transmission and reception through the network, of which hash function possess a key role in various cryptographic protocols. Keccak algorithm is the winner of SHA-3 competition conducted by NIST. SHA-3 consists of different variant such as 224, 256, 384 and 512 bit. This paper discuss the design and implementation of SHA-3 256- bit core. The core is designed using Verilog HDL and prototyped using Xilinx® Virtex®-6FPGA
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