Why IV Setup for Stream Ciphers Is Difficult
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Failures of Secret-Key Cryptography D
Failures of secret-key cryptography D. J. Bernstein University of Illinois at Chicago & Technische Universiteit Eindhoven http://xkcd.com/538/ 2011 Grigg{Gutmann: In the past 15 years \no one ever lost money to an attack on a properly designed cryptosystem (meaning one that didn't use homebrew crypto or toy keys) in the Internet or commercial worlds". 2011 Grigg{Gutmann: In the past 15 years \no one ever lost money to an attack on a properly designed cryptosystem (meaning one that didn't use homebrew crypto or toy keys) in the Internet or commercial worlds". 2002 Shamir:\Cryptography is usually bypassed. I am not aware of any major world-class security system employing cryptography in which the hackers penetrated the system by actually going through the cryptanalysis." Do these people mean that it's actually infeasible to break real-world crypto? Do these people mean that it's actually infeasible to break real-world crypto? Or do they mean that breaks are feasible but still not worthwhile for the attackers? Do these people mean that it's actually infeasible to break real-world crypto? Or do they mean that breaks are feasible but still not worthwhile for the attackers? Or are they simply wrong: real-world crypto is breakable; is in fact being broken; is one of many ongoing disaster areas in security? Do these people mean that it's actually infeasible to break real-world crypto? Or do they mean that breaks are feasible but still not worthwhile for the attackers? Or are they simply wrong: real-world crypto is breakable; is in fact being broken; is one of many ongoing disaster areas in security? Let's look at some examples. -
Statistical Attack on RC4 Distinguishing WPA
Statistical Attack on RC4 Distinguishing WPA Pouyan Sepehrdad, Serge Vaudenay, and Martin Vuagnoux EPFL CH-1015 Lausanne, Switzerland http://lasecwww.epfl.ch Abstract. In this paper we construct several tools for manipulating pools of bi- ases in the analysis of RC4. Then, we show that optimized strategies can break WEP based on 4000 packets by assuming that the first bytes of plaintext are known for each packet. We describe similar attacks for WPA. Firstly, we de- scribe a distinguisher for WPA of complexity 243 and advantage 0.5 which uses 240 packets. Then, based on several partial temporary key recovery attacks, we recover the full 128-bit temporary key by using 238 packets. It works within a complexity of 296. So far, this is the best attack against WPA. We believe that our analysis brings further insights on the security of RC4. 1 Introduction RC4 was designed by Rivest in 1987. It used to be a trade secret until it was anony- mously posted in 1994. Nowadays, RC4 is widely used in SSL/TLS and Wi-Fi 802.11 wireless communications. 802.11 [1] used to be protected by WEP (Wired Equivalent Privacy) which is now being replaced by WPA (Wi-Fi Protected Access) due to security weaknesses. WEP uses RC4 with a pre-shared key. Each packet is encrypted by a XOR to a keystream generated by RC4. The RC4 key is the pre-shared key prepended with a 3- byte nonce IV. The IV is sent in clear for self-synchronization. There have been several attempts to break the full RC4 algorithm but it has only been devastating so far in this scenario. -
Ensuring Fast Implementations of Symmetric Ciphers on the Intel Pentium 4 and Beyond
This may be the author’s version of a work that was submitted/accepted for publication in the following source: Henricksen, Matthew& Dawson, Edward (2006) Ensuring Fast Implementations of Symmetric Ciphers on the Intel Pentium 4 and Beyond. Lecture Notes in Computer Science, 4058, Article number: AISP52-63. This file was downloaded from: https://eprints.qut.edu.au/24788/ c Consult author(s) regarding copyright matters This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the docu- ment is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recog- nise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to [email protected] Notice: Please note that this document may not be the Version of Record (i.e. published version) of the work. Author manuscript versions (as Sub- mitted for peer review or as Accepted for publication after peer review) can be identified by an absence of publisher branding and/or typeset appear- ance. If there is any doubt, please refer to the published source. https://doi.org/10.1007/11780656_5 Ensuring Fast Implementations of Symmetric Ciphers on the Intel Pentium 4 and Beyond Matt Henricksen and Ed Dawson Information Security Institute, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland, 4001, Australia. -
Security in Wireless Sensor Networks Using Cryptographic Techniques
American Journal of Engineering Research (AJER) 2014 American Journal of Engineering Research (AJER) e-ISSN : 2320-0847 p-ISSN : 2320-0936 Volume-03, Issue-01, pp-50-56 www.ajer.org Research Paper Open Access Security in Wireless Sensor Networks using Cryptographic Techniques Madhumita Panda Sambalpur University Institute of Information Technology(SUIIT)Burla, Sambalpur, Odisha, India. Abstract: -Wireless sensor networks consist of autonomous sensor nodes attached to one or more base stations.As Wireless sensor networks continues to grow,they become vulnerable to attacks and hence the need for effective security mechanisms.Identification of suitable cryptography for wireless sensor networks is an important challenge due to limitation of energy,computation capability and storage resources of the sensor nodes.Symmetric based cryptographic schemes donot scale well when the number of sensor nodes increases.Hence public key based schemes are widely used.We present here two public – key based algorithms, RSA and Elliptic Curve Cryptography (ECC) and found out that ECC have a significant advantage over RSA as it reduces the computation time and also the amount of data transmitted and stored. Keywords: -Wireless Sensor Network,Security, Cryptography, RSA,ECC. I. WIRELESS SENSOR NETWORK Sensor networks refer to a heterogeneous system combining tiny sensors and actuators with general- purpose computing elements. These networks will consist of hundreds or thousands of self-organizing, low- power, low-cost wireless nodes deployed to monitor and affect the environment [1]. Sensor networks are typically characterized by limited power supplies, low bandwidth, small memory sizes and limited energy. This leads to a very demanding environment to provide security. -
Hardware Implementation of the Salsa20 and Phelix Stream Ciphers
Hardware Implementation of the Salsa20 and Phelix Stream Ciphers Junjie Yan and Howard M. Heys Electrical and Computer Engineering Memorial University of Newfoundland Email: {junjie, howard}@engr.mun.ca Abstract— In this paper, we present an analysis of the digital of battery limitations and portability, while for virtual private hardware implementation of two stream ciphers proposed for the network (VPN) applications and secure e-commerce web eSTREAM project: Salsa20 and Phelix. Both high speed and servers, demand for high-speed encryption is rapidly compact designs are examined, targeted to both field increasing. programmable (FPGA) and application specific integrated circuit When considering implementation technologies, normally, (ASIC) technologies. the ASIC approach provides better performance in density and The studied designs are specified using the VHDL hardware throughput, but an FPGA is reconfigurable and more flexible. description language, and synthesized by using Synopsys CAD In our study, several schemes are used, catering to the features tools. The throughput of the compact ASIC design for Phelix is of the target technology. 260 Mbps targeted for 0.18µ CMOS technology and the corresponding area is equivalent to about 12,400 2-input NAND 2. PHELIX gates. The throughput of Salsa20 ranges from 38 Mbps for the 2.1 Short Description of the Phelix Algorithm compact FPGA design, implemented using 194 CLB slices to 4.8 Phelix is claimed to be a high-speed stream cipher. It is Gbps for the high speed ASIC design, implemented with an area selected for both software and hardware performance equivalent to about 470,000 2-input NAND gates. evaluation by the eSTREAM project. -
Stream Cipher Designs: a Review
SCIENCE CHINA Information Sciences March 2020, Vol. 63 131101:1–131101:25 . REVIEW . https://doi.org/10.1007/s11432-018-9929-x Stream cipher designs: a review Lin JIAO1*, Yonglin HAO1 & Dengguo FENG1,2* 1 State Key Laboratory of Cryptology, Beijing 100878, China; 2 State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences, Beijing 100190, China Received 13 August 2018/Accepted 30 June 2019/Published online 10 February 2020 Abstract Stream cipher is an important branch of symmetric cryptosystems, which takes obvious advan- tages in speed and scale of hardware implementation. It is suitable for using in the cases of massive data transfer or resource constraints, and has always been a hot and central research topic in cryptography. With the rapid development of network and communication technology, cipher algorithms play more and more crucial role in information security. Simultaneously, the application environment of cipher algorithms is in- creasingly complex, which challenges the existing cipher algorithms and calls for novel suitable designs. To accommodate new strict requirements and provide systematic scientific basis for future designs, this paper reviews the development history of stream ciphers, classifies and summarizes the design principles of typical stream ciphers in groups, briefly discusses the advantages and weakness of various stream ciphers in terms of security and implementation. Finally, it tries to foresee the prospective design directions of stream ciphers. Keywords stream cipher, survey, lightweight, authenticated encryption, homomorphic encryption Citation Jiao L, Hao Y L, Feng D G. Stream cipher designs: a review. Sci China Inf Sci, 2020, 63(3): 131101, https://doi.org/10.1007/s11432-018-9929-x 1 Introduction The widely applied e-commerce, e-government, along with the fast developing cloud computing, big data, have triggered high demands in both efficiency and security of information processing. -
AEGIS: a Fast Authenticated Encryption Algorithm⋆ (Full Version)
AEGIS: A Fast Authenticated Encryption Algorithm? (Full Version) Hongjun Wu1, Bart Preneel2 1 School of Physical and Mathematical Sciences Nanyang Technological University [email protected] 2 Dept. Elektrotechniek-ESAT/COSIC KU Leuven and iMinds, Ghent [email protected] Abstract. This paper introduces a dedicated authenticated encryption algorithm AEGIS; AEGIS allows for the protection of associated data which makes it very suitable for protecting network packets. AEGIS- 128L uses eight AES round functions to process a 32-byte message block (one step). AEGIS-128 uses five AES round functions to process a 16-byte message block (one step); AES-256 uses six AES round functions. The security analysis shows that these algorithms offer a high level of secu- rity. On the Intel Sandy Bridge Core i5 processor, the speed of AEGIS- 128L, AEGIS-128 and AEGIS-256 is around 0.48, 0.66 and 0.7 clock cycles/byte (cpb) for 4096-byte messages, respectively. This is substan- tially faster than the AES CCM, GCM and OCB modes. Key words: Authenticated encryption, AEGIS, AES-NI 1 Introduction The protection of a message typically requires the protection of both confiden- tiality and authenticity. There are two main approaches to authenticate and encrypt a message. One approach is to treat the encryption and authentication separately. The plaintext is encrypted with a block cipher or stream cipher, and a MAC algorithm is used to authenticate the ciphertext. For example, we may apply AES [17] in CBC mode [18] to the plaintext, then apply AES-CMAC [22] (or Pelican MAC [6] or HMAC [19]) to the ciphertext to generate an authen- tication tag. -
MICKEY 2.0. 85: a Secure and Lighter MICKEY 2.0 Cipher Variant With
S S symmetry Article MICKEY 2.0.85: A Secure and Lighter MICKEY 2.0 Cipher Variant with Improved Power Consumption for Smaller Devices in the IoT Ahmed Alamer 1,2,*, Ben Soh 1 and David E. Brumbaugh 3 1 Department of Computer Science and Information Technology, School of Engineering and Mathematical Sciences, La Trobe University, Victoria 3086, Australia; [email protected] 2 Department of Mathematics, College of Science, Tabuk University, Tabuk 7149, Saudi Arabia 3 Techno Authority, Digital Consultant, 358 Dogwood Drive, Mobile, AL 36609, USA; [email protected] * Correspondence: [email protected]; Tel.: +61-431-292-034 Received: 31 October 2019; Accepted: 20 December 2019; Published: 22 December 2019 Abstract: Lightweight stream ciphers have attracted significant attention in the last two decades due to their security implementations in small devices with limited hardware. With low-power computation abilities, these devices consume less power, thus reducing costs. New directions in ultra-lightweight cryptosystem design include optimizing lightweight cryptosystems to work with a low number of gate equivalents (GEs); without affecting security, these designs consume less power via scaled-down versions of the Mutual Irregular Clocking KEYstream generator—version 2-(MICKEY 2.0) cipher. This study aims to obtain a scaled-down version of the MICKEY 2.0 cipher by modifying its internal state design via reducing shift registers and modifying the controlling bit positions to assure the ciphers’ pseudo-randomness. We measured these changes using the National Institutes of Standards and Testing (NIST) test suites, investigating the speed and power consumption of the proposed scaled-down version named MICKEY 2.0.85. -
Lex Mercatoria: Electronic Commerce and Encryption Pages
Lex Mercatoria: Electronic Commerce and Encryption Pages Lex Mercatoria copy @ www.lexmercatoria.org Copyright © 2004 Lex Mercatoria SiSU www.lexmercatoria.org ii Contents Contents Lex Mercatoria: Electronic Commerce and Encryption Pages 1 Electronic Commerce Documents ........................ 1 Cryptography /Encryption ............................. 1 Agreements ................................. 2 Interest Groups ............................... 2 AES Algorithm (Advanced Encryption Standard) ............. 2 Reference and Links ........................... 4 Security Software .............................. 5 Digital Signatures ................................. 8 Electronic Contracts and Electronic Commercial Documents ......... 9 EDI - Electronic Data Interchange ........................ 10 Electronic Payments ................................ 10 Solutions ................................... 10 Discusion .................................. 12 Authentication Solutions - Virtual Identities .................... 14 Government and other Documents: Stands/Approaches to Electronic Com- merce ..................................... 14 Cybercrime ..................................... 15 Privacy ....................................... 15 NoN-Privacy / Security? .......................... 16 Industry ................................... 16 Electronic Commerce Resource Sites ...................... 17 Metadata 19 SiSU Metadata, document information ...................... 19 SiSU www.lexmercatoria.org iii Lex Mercatoria: Electronic Commerce and Encryption Pages -
Iris Um Oifig Maoine Intleachtúla Na Héireann Journal of the Intellectual Property Office of Ireland
Iris um Oifig Maoine Intleachtúla na hÉireann Journal of the Intellectual Property Office of Ireland Iml. 96 Cill Chainnigh 04 August 2021 Uimh. 2443 CLÁR INNSTE Cuid I Cuid II Paitinní Trádmharcanna Leath Leath Official Notice 2355 Official Notice 1659 Applications for Patents 2354 Applications for Trade Marks 1660 Applications Published 2354 Oppositions under Section 43 1717 Patents Granted 2355 Application(s) Amended 1717 European Patents Granted 2356 Application(s) Withdrawn 1719 Applications Withdrawn, Deemed Withdrawn or Trade Marks Registered 1719 Refused 2567 Trade Marks Renewed 1721 Patents Lapsed 2567 International Registrations under the Madrid Request for Grant of Supplementary Protection Protocol 1724 Certificate 2568 International Trade Marks Protected 1735 Supplementary Protection Certificate Granted 2568 Cancellations effected for the following Patents Expired 2570 goods/services under the Madrid protocol 1736 Dearachtaí Designs Information under the 2001 Act Designs Registered 2578 Designs Renewed 2582 The Journal of the Intellectual Property Office of Ireland is published fortnightly. Each issue is freely available to view or download from our website at www.ipoi.gov.ie © Rialtas na hÉireann, 2021 © Government of Ireland, 2021 2353 (04/08/2021) Journal of the Intellectual Property Office of Ireland (No. 2443) Iris um Oifig Maoine Intleachtúla na hÉireann Journal of the Intellectual Property Office of Ireland Cuid I Paitinní agus Dearachtaí No. 2443 Wednesday, 4 August, 2021 NOTE: The office does not guarantee the accuracy of its publications nor undertake any responsibility for errors or omissions or their consequences. In this Part of the Journal, a reference to a section is to a section of the Patents Act, 1992 unless otherwise stated. -
"Analysis and Implementation of RC4 Stream Cipher"
Analysis and Implementation of RC4 Stream Cipher A thesis presented to Indian Statistical Institute in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Computer Science by Sourav Sen Gupta under the supervision of Professor Subhamoy Maitra Applied Statistics Unit INDIAN STATISTICAL INSTITUTE Kolkata, West Bengal, India, 2013 To the virtually endless periods of sweet procrastination that kept me sane during the strenuous one-night stands with my thesis. i ii Abstract RC4 has been the most popular stream cipher in the history of symmetric key cryptography. Designed in 1987 by Ron Rivest, RC4 is the most widely deployed commercial stream cipher, having applications in network protocols such as SSL, WEP, WPA and in Microsoft Windows, Apple OCE, Secure SQL, etc. The enigmatic appeal of the cipher has roots in its simple design, which is undoubtedly the simplest for any practical cryptographic algorithm to date. In this thesis, we focus on the analysis and implementation of RC4. For the first time in RC4 literature, we report significant keystream bi- ases depending on the length of RC4 secret key. In the process, we prove two empirical biases that were experimentally reported and used in recent attacks against WEP and WPA by Sepehrdad, Vaudenay and Vuagnoux in EUROCRYPT 2011. In addition to this, we present a conclusive proof for the extended keylength dependent biases in RC4, a follow-up problem to our keylength dependent results, identified and partially solved by Isobe, Ohigashi, Watanabe and Morii in FSE 2013. In a recent result by AlFardan, Bernstein, Paterson, Poettering and Schuldt, to appear in USENIX Security Symposium 2013, the authors ob- served a bias of the first output byte towards 129. -
Stream Ciphers – an Overview
Stream Ciphers – An Overview Palash Sarkar Indian Statistical Institute, Kolkata email: [email protected] stream cipher overview, Palash Sarkar – p.1/51 Classical Encryption Adversary message ciphertext ciphertext message Encrypt Decrypt public channel secret key K secret key K Adversary’s goal: To obtain message or secret key. stream cipher overview, Palash Sarkar – p.2/51 One Time Pad Let the message be a sequence of bits: ¡£¢¥¤ ¡£¦ ¡©¨ ¤ § § ¤ § ¨ ¢ ¤ Let § § ¤ § be a sequence of random bits. ¨ ¢ ¤ ¦ Ciphertext is ¤ § § ¤ § £ ¡ where . Perfect Secrecy: Given a ciphertext, the message can be any binary string of length . Impractical: (a) Difficult to get random bits. (b) Sequence must be pre-distributed to both sender and receiver. (c) random sequence as long as the message. stream cipher overview, Palash Sarkar – p.3/51 Additive Stream Ciphers Use a pseudorandom generator PRG to produce ¨ ¢¥¤ the sequence § § ¤ § . The PRG extends a short “seed” into a long “pseudorandom” string, i.e., ¡ ¨ ¢¥¤ PRG § § ¤ § . The seed is the secret key . Security depends on the design of PRG. stream cipher overview, Palash Sarkar – p.4/51 Security of PRG PRG is a broad concept. For cryptographic use, a PRG must be unpredictable: Next bit test: Given an initial segment, it should not be possible to efficiently guess the next bit. Statistical Tests: The generated pseudorandom sequence should pass all polynomial time statistical tests. The above notions are equivalent. stream cipher overview, Palash Sarkar – p.5/51 p.6/51 – Sarkar alash P , w ervie v § o (PRP). ¤ ¥ a cipher £ . is stream ¢ ¡ ¤ ¡ © . ¡ cipher § , § © ¤ ¤ permutation £ £ block ¢ . ¢ ¤ ¤ ¡ ¥ ¤ ¡ as £ ¦ -bit ¨ . ¢ y ¤ e ¡ ¤ ¥ k an £ of written ¢ ed ¤ ¡ is Pseudorandom ¡ fix secret called is the ¡ each ¤ Ciphers © is or F Security: permutation Let Block Stream and Block Ciphers Block Ciphers: Applies a fixed permutation to all -bit blocks.