DOCSLIB.ORG

On the Performance of Provably Secure Hashing with Elliptic Curves

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
On the Performance of Provably Secure Hashing with Elliptic Curves IJCSNS International Journal of Computer Science and Network Security, VOL.7 No.10, October 2007 1 On the Performance of Provably Secure Hashing with Elliptic Curves Anton Kargl†, Bernd Meyer†, and Susanne Wetzel†† †Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, 81739 München, Germany ††Stevens Institute of Technology, Hoboken NJ 07030, USA processors. Using several optimizations for the finite field Summary and the elliptic curve arithmetic algebraic hash functions We propose a cryptographic hash function based on the difficulty can be an alternative for practical applications with the of computing discrete logarithms in the group of points of an advantage of provable security. elliptic curve over a finite field. We prove the security of the The remainder of the paper is organized as follows: hash function and analyze the performance. Our implementation in the next section we recapitulate related work and give of the finite field, the elliptic curve arithmetic, and scalar some definitions used in this article. In the third section multiplication is optimized for high throughput on modern 32-bit desktop processors. The achievable data rates allow the use of we prove the security of our hash function. The efficient provably secure hash functions in practical applications. implementation of the hash function is explained in the Key words: fourth section. Hash Function, Elliptic Curve Cryptosystem, Koblitz Curve, Optimal Extension Field, Frobenius Representation. 2. Cryptographic Hash Functions 1. Introduction A cryptographic hash function h is an efficiently computable function of messages with the following The security of all commonly used cryptographic hash properties [23]: functions relies on the heuristic difficulty of • h compresses a message x of arbitrary length to an mathematically modeling and analyzing a wild mix of output h(x) of fixed length, logic and arithmetic operations in the computation of the hash value. Such combinatorial hash functions have many • h is collision resistant, i.e., it is computationally similarities to block ciphers and reach high data rates. infeasible to find distinct messages x and x′ such that Recent results in the analysis of cryptographic hash h(x) = h(x′) . functions using techniques from differential cryptanalysis of block ciphers [2, 3, 33, 32, 34] have cast serious doubts For certain applications hash functions need special on the long-term security of combinatorial hash functions. properties, for example preimage [and second preimage] On the other hand, there exist proposals for hash resistance: for a given hash value y [or for a given message x ] it is computationally infeasible to find a function designs based on algebraic methods and public- 1 key techniques [11, 7, 9]. These functions offer provable preimage x with h(x) = y [or a second preimage x with security in the sense that finding collisions is polynomial- 2 h(x ) = h(x ) ]. It is easy to see, that preimage and second time reducible to the solution of a hard cryptographic 1 2 problem, e.g., the difficulty of computing discrete preimage resistance is implied by collision-resistance. logarithms. The main disadvantage of algebraic hash Often, a hash function consists of a compression functions is their slow data rate caused by long integer function that iteratively hashes message blocks of a fixed arithmetic and the involved mathematical computations for length and the actual internal state of the hash function to the public-key part. the next state. The last computed internal state is the result The aim of this paper is the analysis of the of the hash function. Techniques for padding the message performance and security of an algebraic hash function and encoding their length make sure that a collision of the based on the difficulty of computing discrete logarithms, hash function can be reduced to a collision of the where the arithmetic is based on elliptic curve compression function [11]. cryptography over optimal extension fields and the prime There exist proposals for hash function designs that field arithmetic is optimized for modern 32-bit desktop use symmetric encryption functions as building blocks for Manuscript received October 19, 2007 Manuscript revised October 20, 2007 2 IJCSNS International Journal of Computer Science and Network Security, VOL.7 No.10, October 2007 the compression function of a hash function [24, 10]. For When iterating h as a compression function to build example in [24] the author proposes the compression hash functions for arbitrary length messages (for example 1 function H (.a | b) = Enca (b) ⊕ b Since standard symme- using techniques presented in [11]), one has the problem tric encryption schemes have relatively short key sizes the that the representation of the field elements resulting from compression ratio of the encryption function is low and, an application of h is larger than the values fed back to h. therefore, the performance of the compression function H This reduces the length of the message block that can be is reduced. The security of this scheme relies on the hashed in a single application of h. Even for the case of heuristic assumption that H is a non-invertible random elliptic curves, where it is possible to choose the number function. of points on the curve to be a prime number greater than Nonetheless, modern hash functions, SHA-1 [23], the size of the field, a compressed representation of a point RIPEMD-160 [13], or MD5 [23], use the same principle consists of a field element for the x-coordinate and the of construction. The compression functions of these hash sign of the y-coordinate. functions can be interpreted as a symmetric encryption Moreover, we would like to use Koblitz curves [15] under a very large key followed by a final addition of the which offer faster scalar multiplication over extension plaintext for chaining. Often, the round functions of the fields due to the efficient computation of the Frobenius encryption schemes consist of simple binary and endomorphism. With Koblitz curves the situation is even worse since the number of points can never be a prime: the arithmetic operations in Z 32 that are iterated several 2 order of the subgroup defining the Koblitz curve over the times with different additive constants. This method of prime field always divides the order of the group over the building hash functions yields very efficient algorithms extension field. with high data rates [22, 26]. In the next section we present a hash function based There also exist proposals for hash function designs on elliptic curves. Our construction discards the y- using public-key techniques for the compression functions coordinate of the result of the compression function and [11, 7, 9]. Some of these schemes offer provable security, i. uses m-tuple scalar multiplication to increase the e., finding a collision can be reduced to the solution of a throughput. hard problem, but most have the drawback that the computation of the public-key part needs costly long- integer arithmetic. In [7] Chaum et al. prove the collision-freeness of m- 3. Security of the Compression and the Hash tuple exponentiation and define a provably secure fixed- Function length hash function h based on the discrete logarithm problem in finite groups. In the following we use the In elliptic curve cryptography one considers the set of presentation from [30]: let p be a prime such that all solutions to a non-singular cubic equation q = ( p −1)/ 2 is also prime. Let s1 , s2 ∈ Z p be primitive 2 3 2 y + a1 xy + a3 = x + a2 x + a4 x + a6 over a finite field elements. Assume that the discrete logarithm log s (s2 ) is 1 Fpk . The set forms an additive group, where the neutral not known and that it is computationally infeasible to element O is the point at infinity. Given two points U and compute the logarithm. Given s1, s2 the hash function V on a cryptographically strong curve2 the fastest known 2 h :{0,K, p −1} → Z p is defined as follows: algorithms for the computation of the discrete logarithm log (U ) have exponential running time in the bit-size of h(x , x ) s x1 s x2 mod p . V 1 2 a 1 2 the representation of points [29]. It is shown in [30]: given one collision for the Let E be a cyclic group of points of a function h the discrete logarithm log (s ) can be s1 2 cryptographically strong elliptic curve where ord(E) = q is computed in polynomial time contradicting our a large prime number and let l be the largest integer such assumptions. In [7] this result is generalized to the product l that 2 < q / 2 . Let S1 ,K, S m ∈ E −{O} be randomly of m generators s , , s and message blocks x , , x 1 K m 1 K m chosen pairwise distinct elements. Let ϕ : E → {0,1}u be without analyzing the exact security of the generalized scheme. an efficiently computable mapping which is injective with respect to the x-coordinates, i.e., φ(P) is a representation 1 H (a | b) = Enca (b) ⊕ b denotes encryption of plaintext b under key a and a|b denotes concatenation of the strings a and b. 2We refer for example to [6] for a list of requirements for elliptic curves to be cryptographically strong. IJCSNS International Journal of Computer Science and Network Security, VOL.7 No.10, October 2007 3 of the affine x-coordinate 3 of P with the additional It is easy to check which sign yields the discrete logarithm. property that if φ(P) = φ(P') then we have P = -P' or P = If j ∉{c, d} then it is possible that x j = x′j mod q and the P', and the value u is the size of the representation of the attack fails.
Load more

Recommended publications
  • Hash Functions from Sigma Protocols and Improvements to VSH
    Hash Functions from Sigma Protocols and Improvements to VSH Mihir Bellare and Todor Ristov Department of Computer Science and Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0404, USA. URL: www-cse.ucsd.edu/users/mihir, www-cse.ucsd.edu/users/tristov Abstract. We present a general way to get a provably collision-resistant hash function from any (suitable) Σ-protocol. This enables us to both get new designs and to unify and improve previous work. In the first category, we obtain, via a modified version of the Fiat-Shamir proto- col, the fastest known hash function that is provably collision-resistant based on the standard factoring assumption. In the second category, we provide a modified version VSH* of VSH which is faster when hash- ing short messages. (Most Internet packets are short.) We also show that Σ-hash functions are chameleon, thereby obtaining several new and efficient chameleon hash functions with applications to on-line/off-line signing, chameleon signatures and designated-verifier signatures. 1 Introduction The failure of popular hash functions MD5 and SHA-1 [42, 43] lends an impetus to the search for new ones. The contention of our paper is that there will be a \niche" market for proven-secure even if not-so-fast hash functions. Towards this we provide a general paradigm that yields hash functions provably secure under number-theoretic assumptions, and also unifies, clarifies and improves previous constructs. Our hash functions have extra features such as being chameleon [25]. Let us now look at all this in more detail.
    [Show full text]
  • SSS) Operational Records, 2008-2016
    Description of document: Six (6) Selective Service System (SSS) operational records, 2008-2016 Requested date: January 2017 Released date: 31-January-2017 Posted date: 13-February-2017 Source of document: FOIA Request FOIA Officer Selective Service System National Headquarters Arlington, VA 22209-2425 The governmentattic.org web site (“the site”) is noncommercial and free to the public. The site and materials made available on the site, such as this file, are for reference only. The governmentattic.org web site and its principals have made every effort to make this information as complete and as accurate as possible, however, there may be mistakes and omissions, both typographical and in content. The governmentattic.org web site and its principals shall have neither liability nor responsibility to any person or entity with respect to any loss or damage caused, or alleged to have been caused, directly or indirectly, by the information provided on the governmentattic.org web site or in this file. The public records published on the site were obtained from government agencies using proper legal channels. Each document is identified as to the source. Any concerns about the contents of the site should be directed to the agency originating the document in question. GovernmentAttic.org is not responsible for the contents of documents published on the website. January 31, 2017 This is in response to your Freedom of Information email request dated January, 2017 requesting a digital/electronic copy of the Selective Service System’s following records: 1 Agency National Readiness Plan 2 Call and Deliver Plan 3 Reclassify Plan 4 Alternative Service Plan 5 Lottery Standard Operating Procedures/Plan 6 SSS Fiscal Manual Please note that rather than a Reclassify “Plan” we have a Reclassify “Standard Operating Procedure”.
    [Show full text]
  • Automated Malware Analysis Report for FAKE SSS ID-Pdf
    ID: 214287 Sample Name: FAKE SSS ID- pdf.exe Cookbook: default.jbs Time: 14:43:07 Date: 10/03/2020 Version: 28.0.0 Lapis Lazuli Table of Contents Table of Contents 2 Analysis Report FAKE SSS ID-pdf.exe 4 Overview 4 General Information 4 Detection 4 Confidence 5 Classification Spiderchart 5 Analysis Advice 6 Mitre Att&ck Matrix 6 Signature Overview 7 AV Detection: 7 Spreading: 7 Networking: 7 Key, Mouse, Clipboard, Microphone and Screen Capturing: 8 System Summary: 8 Data Obfuscation: 8 Persistence and Installation Behavior: 8 Hooking and other Techniques for Hiding and Protection: 8 Malware Analysis System Evasion: 9 Anti Debugging: 9 HIPS / PFW / Operating System Protection Evasion: 9 Language, Device and Operating System Detection: 9 Stealing of Sensitive Information: 9 Remote Access Functionality: 9 Malware Configuration 9 Behavior Graph 10 Simulations 10 Behavior and APIs 10 Antivirus, Machine Learning and Genetic Malware Detection 10 Initial Sample 10 Dropped Files 10 Unpacked PE Files 10 Domains 11 URLs 11 Yara Overview 11 Initial Sample 11 PCAP (Network Traffic) 11 Dropped Files 11 Memory Dumps 11 Unpacked PEs 11 Sigma Overview 11 Joe Sandbox View / Context 11 IPs 11 Domains 11 ASN 12 JA3 Fingerprints 12 Dropped Files 12 Screenshots 12 Thumbnails 12 Startup 13 Created / dropped Files 13 Domains and IPs 18 Contacted Domains 18 URLs from Memory and Binaries 18 Contacted IPs 19 Static File Info 19 General 19 File Icon 19 Static PE Info 19 Copyright Joe Security LLC 2020 Page 2 of 36 General 19 Entrypoint Preview 20 Rich Headers 21
    [Show full text]
  • Threshold Cryptography Based on Blakley Secret Sharing
    Threshold Cryptography Based on Blakley Secret Sharing Ilker˙ Nadi Bozkurt, Kamer Kaya, Ali Aydın Selc¸uk Ahmet M. Gulo¨ glu˜ Department of Computer Engineering Department of Mathematics Bilkent University Bilkent University Ankara, 06800, Turkey Ankara, 06800, Turkey Email: bozkurti,kamer,selcuk @cs.bilkent.edu.tr Email: [email protected] f g Abstract—Function sharing deals with the problem and Asmuth-Bloom [1] based on the Chinese Remainder of distribution of the computation of a function (such Theorem. as decryption or signature) among several parties. The A shortcoming of secret sharing schemes is the need to necessary values for the computation are distributed to reveal the secret shares during the reconstruction phase. the participating parties using a secret sharing scheme The system would be more secure if the subject function (SSS). Several function sharing schemes have been pro- posed in the literature, with most of them using Shamir can be computed without revealing the secret shares or secret sharing as the underlying SSS. In this paper, we reconstructing the secret. This is known as the function investigate how threshold cryptography can be conducted sharing problem. A function sharing scheme requires with Blakley secret sharing scheme and present a novel distributing the function’s computation according to the function sharing scheme for the RSA cryptosystem. The underlying SSS such that each part of the computation challenge is that constructing the secret in Blakley’s SSS can be carried out by a different user and then the requires the solution of a linear system which normally partial results can be combined to yield the function’s involves computing inverses, while computing inverses value without disclosing the individual secrets.
    [Show full text]
  • VPC-SI System Administration Guide, Staros Release 21.20
    VPC-SI System Administration Guide, StarOS Release 21.20 First Published: 2020-06-30 Americas Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 527-0883 THE SPECIFICATIONS AND INFORMATION REGARDING THE PRODUCTS IN THIS MANUAL ARE SUBJECT TO CHANGE WITHOUT NOTICE. ALL STATEMENTS, INFORMATION, AND RECOMMENDATIONS IN THIS MANUAL ARE BELIEVED TO BE ACCURATE BUT ARE PRESENTED WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. USERS MUST TAKE FULL RESPONSIBILITY FOR THEIR APPLICATION OF ANY PRODUCTS. THE SOFTWARE LICENSE AND LIMITED WARRANTY FOR THE ACCOMPANYING PRODUCT ARE SET FORTH IN THE INFORMATION PACKET THAT SHIPPED WITH THE PRODUCT AND ARE INCORPORATED HEREIN BY THIS REFERENCE. IF YOU ARE UNABLE TO LOCATE THE SOFTWARE LICENSE OR LIMITED WARRANTY, CONTACT YOUR CISCO REPRESENTATIVE FOR A COPY. The Cisco implementation of TCP header compression is an adaptation of a program developed by the University of California, Berkeley (UCB) as part of UCB's public domain version of the UNIX operating system. All rights reserved. Copyright © 1981, Regents of the University of California. NOTWITHSTANDING ANY OTHER WARRANTY HEREIN, ALL DOCUMENT FILES AND SOFTWARE OF THESE SUPPLIERS ARE PROVIDED “AS IS" WITH ALL FAULTS. CISCO AND THE ABOVE-NAMED SUPPLIERS DISCLAIM ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, THOSE OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OR ARISING FROM A COURSE OF DEALING, USAGE, OR TRADE PRACTICE. IN NO EVENT SHALL CISCO OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT, SPECIAL, CONSEQUENTIAL, OR INCIDENTAL DAMAGES, INCLUDING, WITHOUT LIMITATION, LOST PROFITS OR LOSS OR DAMAGE TO DATA ARISING OUT OF THE USE OR INABILITY TO USE THIS MANUAL, EVEN IF CISCO OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
    [Show full text]
  • Cryptography in Context
    Cryptography in Context Cryptography in Context Gerard Tel iv Contents Contents v Preface ix 1 On the Secure Hash Algorithm family (Wouter Penard and Tim van Werkhoven) 1 1.1 Introduction . 1 1.2 Description of the SHA Algorithms . 4 1.3 Generic Attacks . 8 1.4 Specialized Attacks . 13 1.5 Implications of Attacks . 17 1.6 Conclusion . 17 2 Security and privacy of RFID tags (Jeroen van Wolffelaar) 19 2.1 RFID tags . 19 2.2 Case: Baja Beach Club . 20 2.3 Case: Biometric passports . 22 2.4 Case: OV-chipkaart . 24 2.5 Conclusions . 27 3 Xbox Securtity (Miloslav Valco) 29 3.1 Microsoft's Financial Gambles . 29 3.2 Andrew "bunnie" Huang . 31 3.3 RC4 . 33 3.4 Tiny Encryption Algorithm . 35 3.5 The Visor Hack . 36 3.6 Xbox Linux Project . 36 3.7 Discussion and conclusion . 37 4 Multiple Encryption (Ronald Chu & Mark Jeronimus) 39 4.1 Introduction . 39 4.2 definitions . 40 4.3 Known attacks . 40 4.4 Applications . 45 4.5 Summary and conclusions . 47 v vi Contents 5 Phishing (Marnix Kammer and Barbara Pieters) 49 5.1 Phishing and cryptography . 49 5.2 Forms of phishing . 50 5.3 Changes in human-computer interaction to prevent phishing . 53 5.4 Technical solutions to prevent phishing . 56 5.5 Summary and conclusions . 64 6 Electronic Voting 2.0 (Jeiel Schalkwijk) 67 6.1 The current state of voting machines . 67 6.2 Cryptographic systems . 70 6.3 ThreeBallot . 71 6.4 Moran and Naor's protocol . 72 6.5 Conclusion .
    [Show full text]
  • SSS-V2: Secure Similarity Search Hyun-A Park
    1 SSS-V2: Secure Similarity Search Hyun-A Park Abstract—Encrypting information has been regarded as one of the most substantial approaches to protect users’ sensitive information in radically changing internet technology era. In prior research, researchers have considered similarity search over encrypted documents infeasible, because the single-bit difference of a plaintext would result in an enormous bits difference in the corresponding ciphertext. However, we propose a novel idea of Security Similarity Search (SSS) over encrypted documents by applying character-wise encryption with approximate string matching to keyword index search systems. In order to do this, we define the security requirements of similarity search over encrypted data, propose two similarity search schemes, and formally prove the security of the schemes. The first scheme is more efficient, while the second scheme achieves perfect similarity search privacy. Surprisingly, the second scheme turns out to be faster than other keyword index search schemes with keyword- wise encryption, while enjoying the same level of security. The schemes of SSS support “like query(‘ab%’)” and a query with misprints in that the character-wise encryption preserves the degree of similarity between two plaintexts, and renders approximate string matching between the corresponding ciphertexts possible without decryption. Index Terms—keyword index search, encrypted data, similarity search, character-wise encryption, approximate string matching, hamming distance F 1 INTRODUCTION approximate string matching test. However, simple character-wise N the rapidly developing internet technology era, the amount of encryption is vulnerable to a dictionary attack because the domain I sensitive information radically increases and the information is is too small.
    [Show full text]
  • Bestcrypt Container Encryption Help File
    BestCrypt Container Encryption Help File Introduction Introduction Why do you need BestCrypt? Benefits of BestCrypt BestCrypt Requirements BestCrypt Specifications and Limitations 2 Introduction The BestCrypt Data Encryption system provides the most comprehensive and easy-to-use secure data storage and access control facilities available. BestCrypt’s data encryption method uses encryption algorithms known world-wide and provides unparalleled protection against unauthorized data access. BestCrypt is easy to install, easy to use and totally transparent for application programs. Your data is BestCrypt’s only concern, and it enhances your basic right to keep documents, commercial proprietary knowledge, and private information, in a confidential fashion. See also: Benefits of BestCrypt BestCrypt Requirements BestCrypt Specifications and Limitations 3 Why do you need BestCrypt? BestCrypt is oriented to a wide range of users. Whether you are in business and work with an accounts database, or you are a developer who is designing a new product, or you keep your private correspondence on your computer, you will appreciate a security system that restricts access to your data. With the advent of mass storage systems, a tremendous amount of information can be carried conveniently on even a small notebook computer. What happens to all this information if the computer is stolen at an airport? Suppose someone gains access to your computer without your knowledge. Do you know if your data has been copied and given to someone else? What about the information retained on floppy disks? On portable hard drives? On network drives, where administrators and maybe others can read all unencrypted files? Of course, there are a number of security systems offered for computers, but here is the most important point: The main advantage of BestCrypt is that it is the most powerful, proven protection tool, based on cutting-edge technology, and available now for public use.
    [Show full text]
  • Progress on Cryptography
    PROGRESS ON CRYPTOGRAPHY 25 Years of Cryptography in China THE KLUWER INTERNATIONAL SERIES IN ENGINEERING AND COMPUTER SCIENCE PROGRESS ON CRYPTOGRAPHY 25 Years of Cryptography in China edited by Kefei Chen Shanghai Jiaotong University China KLUWER ACADEMIC PUBLISHERS NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW eBook ISBN: 1-4020-7987-7 Print ISBN: 1-4020-7986-9 ©2004 Kluwer Academic Publishers New York, Boston, Dordrecht, London, Moscow Print ©2004 Kluwer Academic Publishers Boston All rights reserved No part of this eBook may be reproduced or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, without written consent from the Publisher Created in the United States of America Visit Kluwer Online at: http://kluweronline.com and Kluwer's eBookstore at: http://ebooks.kluweronline.com International Workshop on Progress on Cryptography Organized by Department of Computer Science and Engineering, SJTU In cooeration with National Natural Science Foundation of China (NSFC) Aerospace Information Co., Ltd. Workshop Co-Chairs Kefei Chen (Shanghai Jiaotong University, China) Dake He (Southwest Jiaotong University, China) Program committee Kefei Chen (Chair, Shanghai Jiaotong University, China) Lidong Chen (Motorola Inc., USA) Cunsheng Ding (HKUST, Hong Kong, China) Dengguo Feng (Chinese Academy of Sciences, China) Guang Gong (University of Waterloo, Canada) Dake He (Southwest Jiaotong University, China) Xuejia Lai (S.W.I.S. GROUP, Switzerland) Bazhong Shen, (Broadcom Corp., USA) Huafei Zhu (Institute for Infocomm
    [Show full text]
  • Chosen-Ciphertext Attacks Against MOSQUITO
    Chosen-Ciphertext Attacks against MOSQUITO Antoine Joux1,3 and Fr´ed´eric Muller2 1 DGA 2 HSBC-France [email protected] 3 Universit´ede Versailles-Saint-Quentin, France [email protected] Abstract. Self-Synchronizing Stream Ciphers (SSSC) are a particular class of symmetric encryption algorithms, such that the resynchroniza- tion is automatic, in case of error during the transmission of the cipher- text. In this paper, we extend the scope of chosen-ciphertext attacks against SSSC. Previous work in this area include the cryptanalysis of dedi- cated constructions, like KNOT, HBB or SSS. We go further to break the last standing dedicated design of SSSC, i.e. the ECRYPT proposal MOSQUITO. Our attack costs about 270 computation steps, while a 96-bit security level was expected. It also applies to Γ Υ (an ancestor of MOSQUITO) therefore the only secure remaining SSSC are block- cipher-based constructions. 1 Introduction Symmetric encryption algorithms are generally split in two parts : stream ciphers and block ciphers. On the one hand, stream ciphers manipulate the plaintext by short packets of data (for instance bit per bit), using a time-dependent transform. Typically the output of a PRNG (Pseudo-Random Number Gener- ator) is XORed to the plaintext. On the other hand, block ciphers manipulate the plaintext by larger packets of data (typically 128 bits for AES [17]) using a fixed transform. Self-Synchronizing Stream Ciphers (SSSC) are a special primitive : they are often considered as a simple subclass of stream ciphers, but there are also some similarities with block ciphers. Their main property is that, when some error occurs in the transmission of the ciphertext, the decryption algorithm eventually corrects it, after a short sequence of incorrectly decrypted bits.
    [Show full text]
  • Lightweight Password Hashing Scheme for Embedded Systems
    Lightweight Password Hashing Scheme for Embedded Systems George Hatzivasilis1, Ioannis Papaefstathiou1, Charalampos Manifavas2, and Ioannis Askoxylakis3 1 Dept. of Electronic & Computer Engineering, Technical University of Crete, Chania, Crete, Greece [email protected], [email protected] 2 Dept. of Informatics Engineering, Technological Educational Institute of Crete, Heraklion, Crete, Greece [email protected] 3 Foundation for Research and Technology { Hellas (FORTH), Heraklion, Crete, Greece [email protected] Abstract. Passwords constitute the main mean for authentication in computer systems. In order to maintain the user-related information at the service provider end, password hashing schemes (PHS) are uti- lized. The limited and old-fashioned solutions led the international cryp- tographic community to conduct the Password Hashing Competition (PHC). The competition will propose a small portfolio of schemes suit- able for widespread usage until 2015. Embedded systems form a spe- cial application domain, utilizing devices with inherent computational limitations. Lightweight cryptography focuses in designing schemes for such devices and targets moderate levels of security. In this paper, a lightweight poly PHS suitable for lightweight cryptography is presented. At first, we design two lightweight versions of the PHC schemes Catena and PolyPassHash. Then, we integrate them and implement the proposed scheme { called LightPolyPHS. The schemes are applied on a MANET with BeagleBone embedded devices and a fair comparison with similar proposals on mainstream computer is presented. Keywords: password hashing · PHC · Catena · PolyPassHash · lightweight cryptography · LWC · embedded systems · BeagleBone 1 Introduction Attacks on widely known organizations, like SONY [1] and LinkedIn [2], have exposed mounts of user accounts and credentials. The poor password protection practises [3] are exploited by the attackers in order to recover the user passwords from the stolen data.
    [Show full text]
  • Rocca: an Efficient AES-Based Encryption Scheme for Beyond 5G
    IACR Transactions on Symmetric Cryptology ISSN 2519-173X, Vol. 2021, No. 2, pp. 1–30. DOI:10.46586/tosc.v2021.i2.1-30 Rocca: An Efficient AES-based Encryption Scheme for Beyond 5G Kosei Sakamoto1 and Fukang Liu1,2 and Yuto Nakano3 and Shinsaku Kiyomoto3 and Takanori Isobe1,4,5 1 University of Hyogo, Kobe, Japan. [email protected], [email protected], [email protected] 2 East China Normal University, Shanghai, China 3 KDDI Research, Fujimino, Japan. [email protected], [email protected] 4 National Institute of Information and Communications Technology (NICT), Tokyo, Japan 5 PRESTO, Japan Science and Technology Agency, Tokyo, Japan Abstract. In this paper, we present an AES-based authenticated-encryption with associated-data scheme called Rocca, with the purpose to reach the requirements on the speed and security in 6G systems. To achieve ultra-fast software implementations, the basic design strategy is to take full advantage of the AES-NI and SIMD instructions as that of the AEGIS family and Tiaoxin-346. Although Jean and Nikolić have generalized the way to construct efficient round functions using only one round of AES (aesenc) and 128-bit XOR operation and have found several efficient candidates, there still seems to exist potential to further improve it regarding speed and state size. In order to minimize the critical path of one round, we remove the case of applying both aesenc and XOR in a cascade way for one round. By introducing a cost-free block permutation in the round function, we are able to search for candidates in a larger space without sacrificing the performance.
    [Show full text]