Time-Locked Encryption Made Practical
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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. -
Introduction to Public Key Cryptography and Clock Arithmetic Lecture Notes for Access 2010, by Erin Chamberlain and Nick Korevaar
1 Introduction to Public Key Cryptography and Clock Arithmetic Lecture notes for Access 2010, by Erin Chamberlain and Nick Korevaar We’ve discussed Caesar Shifts and other mono-alphabetic substitution ciphers, and we’ve seen how easy it can be to break these ciphers by using frequency analysis. If Mary Queen of Scots had known this, perhaps she would not have been executed. It was a long time from Mary Queen of Scots and substitution ciphers until the end of the 1900’s. Cryptography underwent the evolutionary and revolutionary changes which Si- mon Singh chronicles in The Code Book. If you are so inclined and have appropriate leisure time, you might enjoy reading Chapters 2-5, to learn some of these historical cryptography highlights: People came up with more complicated substitution ciphers, for example the Vigen`ere square. This Great Cipher of France baffled people for quite a while but a de- termined cryptographer Etienne Bazeries had a Eureka moment after three years of work, cracked the code, and possibly found the true identity of the Man in the Iron Mask, one of the great mysteries of the seventeeth century. Edgar Allan Poe and Sir Arthur Conan Doyle even dabbled in cryptanalysis. Secrecy was still a problem though because the key needed to be sent, and with the key anyone could encrypt and decrypt the messages. Frequency analysis was used to break all of these codes. In 1918 Scherbius invented his Enigma machine, but Alan Turing’s machine (the first computer?) helped in figuring out that supposedly unbreakable code, and hastened the end of the second World War. -
The Mathemathics of Secrets.Pdf
THE MATHEMATICS OF SECRETS THE MATHEMATICS OF SECRETS CRYPTOGRAPHY FROM CAESAR CIPHERS TO DIGITAL ENCRYPTION JOSHUA HOLDEN PRINCETON UNIVERSITY PRESS PRINCETON AND OXFORD Copyright c 2017 by Princeton University Press Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock, Oxfordshire OX20 1TR press.princeton.edu Jacket image courtesy of Shutterstock; design by Lorraine Betz Doneker All Rights Reserved Library of Congress Cataloging-in-Publication Data Names: Holden, Joshua, 1970– author. Title: The mathematics of secrets : cryptography from Caesar ciphers to digital encryption / Joshua Holden. Description: Princeton : Princeton University Press, [2017] | Includes bibliographical references and index. Identifiers: LCCN 2016014840 | ISBN 9780691141756 (hardcover : alk. paper) Subjects: LCSH: Cryptography—Mathematics. | Ciphers. | Computer security. Classification: LCC Z103 .H664 2017 | DDC 005.8/2—dc23 LC record available at https://lccn.loc.gov/2016014840 British Library Cataloging-in-Publication Data is available This book has been composed in Linux Libertine Printed on acid-free paper. ∞ Printed in the United States of America 13579108642 To Lana and Richard for their love and support CONTENTS Preface xi Acknowledgments xiii Introduction to Ciphers and Substitution 1 1.1 Alice and Bob and Carl and Julius: Terminology and Caesar Cipher 1 1.2 The Key to the Matter: Generalizing the Caesar Cipher 4 1.3 Multiplicative Ciphers 6 -
The Enigma History and Mathematics
The Enigma History and Mathematics by Stephanie Faint A thesis presented to the University of Waterloo in fulfilment of the thesis requirement for the degree of Master of Mathematics m Pure Mathematics Waterloo, Ontario, Canada, 1999 @Stephanie Faint 1999 I hereby declare that I am the sole author of this thesis. I authorize the University of Waterloo to lend this thesis to other institutions or individuals for the purpose of scholarly research. I further authorize the University of Waterloo to reproduce this thesis by pho tocopying or by other means, in total or in part, at the request of other institutions or individuals for the purpose of scholarly research. 11 The University of Waterloo requires the signatures of all persons using or pho tocopying this thesis. Please sign below, and give address and date. ill Abstract In this thesis we look at 'the solution to the German code machine, the Enigma machine. This solution was originally found by Polish cryptologists. We look at the solution from a historical perspective, but most importantly, from a mathematical point of view. Although there are no complete records of the Polish solution, we try to reconstruct what was done, sometimes filling in blanks, and sometimes finding a more mathematical way than was originally found. We also look at whether the solution would have been possible without the help of information obtained from a German spy. IV Acknowledgements I would like to thank all of the people who helped me write this thesis, and who encouraged me to keep going with it. In particular, I would like to thank my friends and fellow grad students for their support, especially Nico Spronk and Philippe Larocque for their help with latex. -
Encryption Is Futile: Delay Attacks on High-Precision Clock Synchronization 1
R. ANNESSI, J. FABINI, F.IGLESIAS, AND T. ZSEBY: ENCRYPTION IS FUTILE: DELAY ATTACKS ON HIGH-PRECISION CLOCK SYNCHRONIZATION 1 Encryption is Futile: Delay Attacks on High-Precision Clock Synchronization Robert Annessi, Joachim Fabini, Felix Iglesias, and Tanja Zseby Institute of Telecommunications TU Wien, Austria Email: fi[email protected] Abstract—Clock synchronization has become essential to mod- endanger control decisions, and adversely affect the overall ern societies since many critical infrastructures depend on a functionality of a wide range of (critical) services that depend precise notion of time. This paper analyzes security aspects on accurate time. of high-precision clock synchronization protocols, particularly their alleged protection against delay attacks when clock syn- In recent years, security of clock synchronization received chronization traffic is encrypted using standard network security increased attention as various attacks on clock synchronization protocols such as IPsec, MACsec, or TLS. We use the Precision protocols (and countermeasures) were proposed. For this Time Protocol (PTP), the most widely used protocol for high- reason, clock synchronization protocols need to be secured precision clock synchronization, to demonstrate that statistical whenever used outside of fully trusted network environments. traffic analysis can identify properties that support selective message delay attacks even for encrypted traffic. We furthermore Clock synchronization protocols are specifically susceptible to identify a fundamental conflict in secure clock synchronization delay attacks since the times when messages are sent and between the need of deterministic traffic to improve precision and received have an actual effect on the receiver’s notion of the need to obfuscate traffic in order to mitigate delay attacks. -
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”. -
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 -
Towards Low Energy Stream Ciphers
IACR Transactions on Symmetric Cryptology ISSN 2519-173X, Vol. 2018, No. 2, pp. 1–19. DOI:10.13154/tosc.v2018.i2.1-19 Towards Low Energy Stream Ciphers Subhadeep Banik1, Vasily Mikhalev2, Frederik Armknecht2, Takanori Isobe3, Willi Meier4, Andrey Bogdanov5, Yuhei Watanabe6 and Francesco Regazzoni7 1 Security and Cryptography Laboratory (LASEC), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland [email protected] 2 University of Mannheim, Mannheim, Germany {mikhalev,armknecht}@uni-mannheim.de 3 University of Hyogo, Hyogo, Japan [email protected] 4 University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Windisch, Switzerland [email protected] 5 Department of Applied Mathematics and Computer Science (DTU Compute), Technical University of Denmark, Kongens Lyngby, Denmark [email protected] 6 National Institute of Advanced Industrial Science and Technology, Osaka, Japan [email protected] 7 Università della Svizzera italiana (USI), Lugano, Switzerland [email protected] Abstract. Energy optimization is an important design aspect of lightweight cryptog- raphy. Since low energy ciphers drain less battery, they are invaluable components of devices that operate on a tight energy budget such as handheld devices or RFID tags. At Asiacrypt 2015, Banik et al. presented the block cipher family Midori which was designed to optimize the energy consumed per encryption and which reduces the energy consumption by more than 30% compared to previous block ciphers. However, if one has to encrypt/decrypt longer streams of data, i.e. for bulk data encryption/decryption, it is expected that a stream cipher should perform even better than block ciphers in terms of energy required to encrypt. -
Design of an Efficient Architecture for Advanced Encryption Standard Algorithm Using Systolic Structures
International Conference of High Performance Computing (HiPC 2005) Design of an Efficient Architecture for Advanced Encryption Standard Algorithm Using Systolic Structures 1Suresh Sharma, 2T S B Sudarshan 1Student, Computer Science & Engineering, IIT, Khragpur 2 Assistant Professor, Computer Science & Information Systems, BITS, Pilani. fashion and communication with the memory or Abstract: external devices occurs only through the boundary This Paper presents a systolic architecture for cells. Advanced Encryption standard (AES). Use of systolic The architecture uses similarities of encryption and architecture has improved the hardware complexity decryption to provide a high level of performance and the rate of encryption/decryption. Similarities of while keeping the chip size small. The architecture encryption and decryption are used to provide a high is highly regular and scalable. The key size can performance using an efficient architecture. The easily be changed from 128 to 192 or 256 bits by efficiency of the design is quite high due to use of making very few changes in the design. short and balanced combinational paths in the design. The paper is organized as follows. Section 2 gives a The encryption or decryption rate is 3.2-Bits per brief overview of the AES algorithm. In section 3, a clock-cycle and due to the use of pipelined systolic summary of available AES architecture is given and architecture and balanced combinational paths the proposed AES hardware architecture is maximum clock frequency for the design is quite described. The performance of the architecture is high. compared with other implementations in section 4. Concluding remarks are given in section 5. Index terms:- Advanced Encryption standard (AES), Systolic Architecture, processing elements, 2. -
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. -
Cumulative Message Authentication Codes for Resource
1 Cumulative Message Authentication Codes for Resource-Constrained IoT Networks He Li, Vireshwar Kumar, Member, IEEE, Jung-Min (Jerry) Park, Fellow, IEEE, and Yaling Yang, Member, IEEE Abstract—In resource-constrained IoT networks, the use of problems: the computational burden on the devices for gen- conventional message authentication codes (MACs) to provide erating/verifying the MAC, and the additional communication message authentication and integrity is not possible due to the overhead incurred due to the inclusion of the MAC in each large size of the MAC output. A straightforward yet naive solution to this problem is to employ a truncated MAC which message frame/packet. The first problem can be addressed by undesirably sacrifices cryptographic strength in exchange for using dedicated hardware and cryptographic accelerators [11], reduced communication overhead. In this paper, we address this [31]. However, the second problem is not as easy to address. problem by proposing a novel approach for message authentica- tion called Cumulative Message Authentication Code (CuMAC), Problem. The cryptographic strength of a MAC depends which consists of two distinctive procedures: aggregation and on the cryptographic strength of the underlying cryptographic accumulation. In aggregation, a sender generates compact au- primitive (e.g. a hash or block cipher), the size and quality of thentication tags from segments of multiple MACs by using a systematic encoding procedure. In accumulation, a receiver the key, and the size of the MAC output. Hence, a conventional accumulates the cryptographic strength of the underlying MAC MAC scheme typically employs at least a few hundred bits by collecting and verifying the authentication tags. -
Implementation of Symmetric Algorithms on a Synthesizable 8-Bit Microcontroller Targeting Passive RFID Tags
Implementation of Symmetric Algorithms on a Synthesizable 8-Bit Microcontroller Targeting Passive RFID Tags Thomas Plos, Hannes Groß, and Martin Feldhofer Institute for Applied Information Processing and Communications (IAIK), Graz University of Technology, Inffeldgasse 16a, 8010 Graz, Austria {Thomas.Plos,Martin.Feldhofer}@iaik.tugraz.at, [email protected] Abstract. The vision of the secure Internet-of-Things is based on the use of security-enhanced RFID technology. In this paper, we describe the implementation of symmetric-key primitives on passive RFID tags. Our approach uses a fully synthesizable 8-bit microcontroller that executes, in addition to the communication protocol, also various cryptographic algorithms. The microcontroller was designed to fulfill the fierce con- straints concerning chip area and power consumption in passive RFID tags. The architecture is flexible in terms of used program size and the number of used registers which allows an evaluation of various algorithms concerning their required resources. We analyzed the block ciphers AES, SEA, Present and XTEA as well as the stream cipher Trivium. The achieved results show that our approach is more efficient than other ded- icated microcontrollers and even better as optimized hardware modules when considering the combination of controlling tasks on the tag and executing cryptographic algorithms. Keywords: passive RFID tags, 8-bit microcontroller, symmetric-key al- gorithms, low-resource hardware implementation. 1 Introduction Radio frequency identification (RFID) is the enabler technology for the future Internet-of-Things (IoT), which allows objects to communicate with each other. The ability to uniquely identify objects opens the door for a variety of new applications.