Combining Message Encryption and Authentication
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Advanced Encryption Standard Real-World Alternatives
Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives CPSC 367: Cryptography and Security Michael Fischer Lecture 7 February 5, 2019 Thanks to Ewa Syta for the slides on AES CPSC 367, Lecture 7 1/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Multiple Encryption Composition Group property Birthday Attack Advanced Encryption Standard AES Real-World Issues Alternative Private Key Block Ciphers CPSC 367, Lecture 7 2/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Multiple Encryption CPSC 367, Lecture 7 3/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Composition Composition of cryptosystems Encrypting a message multiple times with the same or different ciphers and keys seems to make the cipher stronger, but that's not always the case. The security of the composition can be difficult to analyze. For example, with the one-time pad, the encryption and decryption functions Ek and Dk are the same. The composition Ek ◦ Ek is the identity function! CPSC 367, Lecture 7 4/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Composition Composition within practical cryptosystems Practical symmetric cryptosystems such as DES and AES are built as a composition of simpler systems. Each component offers little security by itself, but when composed, the layers obscure the message to the point that it is difficult for an adversary to recover. The trick is to find ciphers that successfully hide useful information from a would-be attacker when used in concert. CPSC 367, Lecture 7 5/58 Outline Multiple Encryption Birthday Attack Advanced Encryption Standard Real-World Alternatives Composition Double Encryption Double encryption is when a cryptosystem is composed with itself. -
The Data Encryption Standard (DES) – History
Chair for Network Architectures and Services Department of Informatics TU München – Prof. Carle Network Security Chapter 2 Basics 2.1 Symmetric Cryptography • Overview of Cryptographic Algorithms • Attacking Cryptographic Algorithms • Historical Approaches • Foundations of Modern Cryptography • Modes of Encryption • Data Encryption Standard (DES) • Advanced Encryption Standard (AES) Cryptographic algorithms: outline Cryptographic Algorithms Symmetric Asymmetric Cryptographic Overview En- / Decryption En- / Decryption Hash Functions Modes of Cryptanalysis Background MDC’s / MACs Operation Properties DES RSA MD-5 AES Diffie-Hellman SHA-1 RC4 ElGamal CBC-MAC Network Security, WS 2010/11, Chapter 2.1 2 Basic Terms: Plaintext and Ciphertext Plaintext P The original readable content of a message (or data). P_netsec = „This is network security“ Ciphertext C The encrypted version of the plaintext. C_netsec = „Ff iThtIiDjlyHLPRFxvowf“ encrypt key k1 C P key k2 decrypt In case of symmetric cryptography, k1 = k2. Network Security, WS 2010/11, Chapter 2.1 3 Basic Terms: Block cipher and Stream cipher Block cipher A cipher that encrypts / decrypts inputs of length n to outputs of length n given the corresponding key k. • n is block length Most modern symmetric ciphers are block ciphers, e.g. AES, DES, Twofish, … Stream cipher A symmetric cipher that generats a random bitstream, called key stream, from the symmetric key k. Ciphertext = key stream XOR plaintext Network Security, WS 2010/11, Chapter 2.1 4 Cryptographic algorithms: overview -
Analysis of Selected Block Cipher Modes for Authenticated Encryption
Analysis of Selected Block Cipher Modes for Authenticated Encryption by Hassan Musallam Ahmed Qahur Al Mahri Bachelor of Engineering (Computer Systems and Networks) (Sultan Qaboos University) – 2007 Thesis submitted in fulfilment of the requirement for the degree of Doctor of Philosophy School of Electrical Engineering and Computer Science Science and Engineering Faculty Queensland University of Technology 2018 Keywords Authenticated encryption, AE, AEAD, ++AE, AEZ, block cipher, CAESAR, confidentiality, COPA, differential fault analysis, differential power analysis, ElmD, fault attack, forgery attack, integrity assurance, leakage resilience, modes of op- eration, OCB, OTR, SHELL, side channel attack, statistical fault analysis, sym- metric encryption, tweakable block cipher, XE, XEX. i ii Abstract Cryptography assures information security through different functionalities, es- pecially confidentiality and integrity assurance. According to Menezes et al. [1], confidentiality means the process of assuring that no one could interpret infor- mation, except authorised parties, while data integrity is an assurance that any unauthorised alterations to a message content will be detected. One possible ap- proach to ensure confidentiality and data integrity is to use two different schemes where one scheme provides confidentiality and the other provides integrity as- surance. A more compact approach is to use schemes, called Authenticated En- cryption (AE) schemes, that simultaneously provide confidentiality and integrity assurance for a message. AE can be constructed using different mechanisms, and the most common construction is to use block cipher modes, which is our focus in this thesis. AE schemes have been used in a wide range of applications, and defined by standardisation organizations. The National Institute of Standards and Technol- ogy (NIST) recommended two AE block cipher modes CCM [2] and GCM [3]. -
Implementation and Analysis of Key Reinstallation Attack
International Journal of Innovations in Engineering and Technology (IJIET) http://dx.doi.org/10.21172/ijiet.133.21 Implementation and Analysis of Key Reinstallation Attack Saba Khanum1, Ishita kalra2 1Department of Information Technology, MSIT, Janakpuri, New Delhi, India 2Department of Computer Science and Engineering, MSIT, Janakpuri, New Delhi, India Abstract- The objective of the paper is to implement and analyzed the impact of Key Reinstallation Attack (popularly dubbed as KRACK) on debian based machines. The paper elucidates on the capture of packets through the attack without being a part of the network and affecting the target machines with the help of an attack machine placed inside the network. It basically exploits the nonce of the network which ultimately paves way to the execution of the attack. The issue tends to gather more eyeballs as it affects all devices using Wi-Fi through WPA2 protocol. Hence, the catastrophe complimented along the attack is severe. The analysis of the impact is carried on by analyzing the type of packets visible as well as captured during the course of the implementation. Here, we have created a python script which identifies whether the targeted machine is vulnerable to KRACK or not and corresponding to that the packet capture starts and ultimately, the impact is measured. Keywords – KRACK, weakness, WPA2, attack, security I. INTRODUCTION The presence of the bug has been detected in the cryptographic nonce of the WPA2 and can be used to clone a connected party to reinstall a used key. The presence of the nonce is specifically intended to prevent reuse, but in this particular case, it gives malicious users the opportunity to replay, decrypt, or forge packets, ultimately enabling them to access all previously considered encrypted information without actually being part of the network. -
Authenticated Encryption for Memory Constrained Devices
Authenticated Encryption for Memory Constrained Devices By Megha Agrawal A thesis submitted in partial fulfillment for the degree of Doctor of Philosophy in Computer Science & Engineering to the Indraprastha Institute of Information Technology, Delhi (IIIT-Delhi) Supervisors: Dr. Donghoon Chang (IIIT Delhi) Dr. Somitra Sanadhya (IIT Jodhpur) September 2020 Certificate This is to certify that the thesis titled - \Authenticated Encryption for Memory Constrained Devices" being submitted by Megha Agrawal to Indraprastha Institute of Information Technology, Delhi, for the award of the degree of Doctor of Philosophy, is an original research work carried out by her under our supervision. In our opinion, the thesis has reached the standards fulfilling the requirements of the regulations relating to the degree. The results contained in this thesis have not been submitted in part or full to any other university or institute for the award of any degree/diploma. Dr. Donghoon Chang September, 2020 Department of Computer Science Indraprastha Institute of Information Technology, Delhi New Delhi, 110020 ii To my family Acknowledgments Firstly, I would like to express my sincere gratitude to my advisor Dr. Donghoon Chang for the continuous support of my Ph.D study and related research, for his patience, motivation, and immense knowledge. His guidance helped me in all the time of research and writing of this thesis. I could not have imagined having a better advisor and mentor for my Ph.D study. I also express my sincere gratitude to my esteemed co-advisor, Dr. Somitra Sanadhya, who has helped me immensely throughout my Ph.D. life. I thank my fellow labmates for the stimulating discussions, and for all the fun we have had in during these years. -
The EAX Mode of Operation
A preliminary version of this papers appears in Fast Software Encryption ’04, Lecture Notes in Computer Science, vol. ?? , R. Bimal and W. Meier ed., Springer-Verlag, 2004. This is the full version. The EAX Mode of Operation (A Two-Pass Authenticated-Encryption Scheme Optimized for Simplicity and Efficiency) ∗ † ‡ M. BELLARE P. ROGAWAY D. WAGNER January 18, 2004 Abstract We propose a block-cipher mode of operation, EAX, for solving the problem of authenticated-encryption with associated-data (AEAD). Given a nonce N, a message M, and a header H, our mode protects the privacy of M and the authenticity of both M and H. Strings N, M, and H are arbitrary bit strings, and the mode uses 2|M|/n + |H|/n + |N|/n block-cipher calls when these strings are nonempty and n is the block length of the underlying block cipher. Among EAX’s characteristics are that it is on-line (the length of a message isn’t needed to begin processing it) and a fixed header can be pre-processed, effectively removing the per-message cost of binding it to the ciphertext. EAX is obtained by first creating a generic-composition method, EAX2, and then collapsing its two keys into one. EAX is provably secure under a standard complexity-theoretic assumption. The proof of this fact is novel and involved. EAX is an alternative to CCM [26], which was created to answer the wish within standards bodies for a fully-specified and patent-free AEAD mode. As such, CCM and EAX are two-pass schemes, with one pass for achieving privacy and one for authenticity. -
Security Policy: Informacast Java Crypto Library
FIPS 140-2 Non-Proprietary Security Policy: InformaCast Java Crypto Library FIPS 140-2 Non-Proprietary Security Policy InformaCast Java Crypto Library Software Version 3.0 Document Version 1.2 June 26, 2017 Prepared For: Prepared By: Singlewire Software SafeLogic Inc. 1002 Deming Way 530 Lytton Ave, Suite 200 Madison, WI 53717 Palo Alto, CA 94301 www.singlewire.com www.safelogic.com Document Version 1.2 © Singlewire Software Page 1 of 35 FIPS 140-2 Non-Proprietary Security Policy: InformaCast Java Crypto Library Abstract This document provides a non-proprietary FIPS 140-2 Security Policy for InformaCast Java Crypto Library. Document Version 1.2 © Singlewire Software Page 2 of 35 FIPS 140-2 Non-Proprietary Security Policy: InformaCast Java Crypto Library Table of Contents 1 Introduction .................................................................................................................................................. 5 1.1 About FIPS 140 ............................................................................................................................................. 5 1.2 About this Document.................................................................................................................................... 5 1.3 External Resources ....................................................................................................................................... 5 1.4 Notices ......................................................................................................................................................... -
Multiple Results on Multiple Encryption
Multiple Results on Multiple Encryption Itai Dinur, Orr Dunkelman, Nathan Keller, and Adi Shamir The Security of Multiple Encryption: Given a block cipher with n-bit plaintexts and n-bit keys, we would like to enhance its security via sequential composition Assuming that – the basic block cipher has no weaknesses – the k keys are independently chosen how secure is the resultant composition? P C K1 K2 K3 K4 Double and Triple Encryptions: Double DES and triple DES were widely used by banks, so their security was thoroughly analyzed By using a Meet in the Middle (MITM) attack, Diffie and Hellman showed in 1981 that double encryption can be broken in T=2^n time and S=2^n space. Note that TS=2^{2n} Given the same amount of space S=2^n, we can break triple encryption in time T=2^{2n}, so again TS=2^{3n} How Secure is k-encryption for k>3? The fun really starts at quadruple encryption (k=4), which was not well studied so far, since we can show that breaking 4-encryption is not harder than breaking 3-encryption when we use 2^n space! Our new attacks: – use the smallest possible amount of data (k known plaintext/ciphertext pairs which are required to uniquely define the k keys) – Never err (if there is a solution, it will always be found) The time complexity of our new attacks (expressed by the coefficient c in the time formula T=2^{cn}) k = c = The time complexity of our new attacks (expressed by the coefficient c in the time formula T=2^{cn}) k = 2 c = 1 The time complexity of our new attacks (expressed by the coefficient c in the time -
Efficient & Secure Cipher Scheme with Dynamic Key-Dependent Mode Of
Efficient & secure cipher scheme with dynamic key-dependent mode of operation Hassan Noura, Ali Chehab, Raphael Couturier To cite this version: Hassan Noura, Ali Chehab, Raphael Couturier. Efficient & secure cipher scheme with dynamic key- dependent mode of operation. Signal Processing: Image Communication, Elsevier, 2019, 78, pp.448 - 464. hal-02366798 HAL Id: hal-02366798 https://hal.archives-ouvertes.fr/hal-02366798 Submitted on 16 Nov 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Efficient & Secure Cipher Scheme with Dynamic Key-Dependent Mode of Operation Hassan N. Nouraa, Ali Chehaba, Rapha¨elCouturierb a Electrical and Computer Engineering American University of Beirut (AUB) Beirut, Lebanon bUniv. Bourgogne Franche-Comt´e(UBFC), FEMTO-ST Institute, CNRS, Belfort, France Abstract Security attacks are constantly on the rise leading to drastic consequences. Several secu- rity services are required more than ever to prevent both passive and active attacks such as Data Confidentiality (DC). A DC security service is typically based on a strong symmetric cipher algorithm. However, some of today's applications, such as real-time applications and those running on constrained devices, require efficient lightweight cipher schemes that can achieve a good balance between the security level and system performance. -
Aes Encryption Java Example Code
Aes Encryption Java Example Code Emerging and gleg Whitby enduing: which Paten is minuscule enough? Emasculate Roderic evaded aversely while Hamel always incinerated his trio decollating ontogenetically, he ferment so scrutinizingly. Sargent is top-level and dialogised esuriently while alchemical Rickey delimitated and claw. How to Encrypt and Decrypt using AES in Java JavaPointers. Typically the first time any longer preclude subsequent encryption attempts. Java AES encryption and decryption with static secret. Strategies to keep IV The IV used to encrypt the message is best to decrypting the message therefore leaving question is raised, the data contained in multiple files should have used several keys to encrypt the herd thus bringing down risk of character total exposure loss. AES Encryption with HMAC Integrity in Java netnixorg. AES was developed by two belgian cryptographers. Gpg key example, aes encryption java service encrypt text file, and is similar to connect to read the codes into different. It person talk about creating AES keys and storing AES keys in a JCEKS keystore format. As a predecessor value initialization vector using os. Where to Go live Here? Cipher to took the data bank it is passed to the underlying stream. This code if you use aes? Change i manage that you how do. Copyright The arc Library Authors. First house get an arms of Cipher for your chosen encryption type. To encrypt the dom has access to java encryption? You would do the encryption java service for file transfer to. The java or? Find being on Facebook and Twitter. There put two ways for generating a digit key is used on each router that use. -
Modes of Operation Module No: CS/CNS/1
e-PGPathshala Subject : Computer Science Paper: Cryptography and Network Security Module: Modes of Operation Module No: CS/CNS/18 Quadrant 1 – e-text Cryptography and Network Security Module 18- Modes of Operation Learning Objectives To understand the Overview of Modes of Operation Discuss about each mode of operation such as EBC, CBC, CFB, OFB, CTR To Compare different modes and to discuss remarks over them 18.1. INTRODUCTION So far we have seen the basic working of block ciphers. In this section, we discuss about modes of operation of block ciphers. Basically the lengthy plain text is divided into number of blocks in block ciphers. Block ciphers encrypt fixed size blocks eg. DES encrypts 64-bit blocks, with 56-bit key. But in actual scenario, the file size which has to be encrypted may not be the multiple of the block size. That is in practise, we usually need to handle arbitrary amounts of data, which may be available in advance (in which case a block mode is appropriate), and may only be available a bit/byte at a time (in which case a stream mode is used). A mode of operation describes the process of encrypting each of these blocks under a single key. A mode of operation describes the process of encrypting each of these blocks under a single key. Some modes may use randomised addition input value. We can apply a particular mode of operation in this situation. Basic modes of operations such as Electronic Code Book(ECB), Cipher Block Chaining(CBC), Cipher Feed Back (CFB), Output Feed Back (OFB), Counter (CTR) modes are considered here. -
Authenticated Encryption Mode IAPM Using SHA-3'S Public Random
Authenticated Encryption Mode IAPM using SHA-3’s Public Random Permutation Charanjit Jutla IBM T. J. Watson Research Center New York 10598 Abstract. We study instantiating the random permutation of the block- cipher mode of operation IAPM (Integrity-Aware Parallelizable Mode) with the public random permutation of Keccak, on which the draft stan- dard SHA-3 is built. IAPM and the related mode OCB are single-pass highly parallelizable authenticated-encryption modes, and while they were originally proven secure in the private random permutation model, Kurosawa has shown that they are also secure in the public random per- mutation model assuming the whitening keys are uniformly chosen with double the usual entropy. In this paper, we show a general composabil- ity result that shows that the whitening key can be obtained from the usual entropy source by a key-derivation function which is itself built on Keccak. We stress that this does not follow directly from the usual indifferentiability of key-derivation function constructions from Random Oracles. We also show that a simple and general construction, again employing Keccak, can also be used to make the IAPM scheme key- dependent-message secure. Finally, implementations on modern AMD-64 architecture supporting 128-bit SIMD instructions, and not supporting the native AES instructions, show that IAPM with Keccak runs three times faster than IAPM with AES. 1 Introduction Symmetric key encryption of bulk data is usually performed using either a stream cipher or a block cipher. A long message is divided into small fixed-size blocks and encryption is performed by either a stream-cipher mode or a block-cipher mode employing a cryptographic primitive that operates on blocks.