Key Derivation and Randomness Extraction
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Public-Key Cryptography
Public Key Cryptography EJ Jung Basic Public Key Cryptography public key public key ? private key Alice Bob Given: Everybody knows Bob’s public key - How is this achieved in practice? Only Bob knows the corresponding private key Goals: 1. Alice wants to send a secret message to Bob 2. Bob wants to authenticate himself Requirements for Public-Key Crypto ! Key generation: computationally easy to generate a pair (public key PK, private key SK) • Computationally infeasible to determine private key PK given only public key PK ! Encryption: given plaintext M and public key PK, easy to compute ciphertext C=EPK(M) ! Decryption: given ciphertext C=EPK(M) and private key SK, easy to compute plaintext M • Infeasible to compute M from C without SK • Decrypt(SK,Encrypt(PK,M))=M Requirements for Public-Key Cryptography 1. Computationally easy for a party B to generate a pair (public key KUb, private key KRb) 2. Easy for sender to generate ciphertext: C = EKUb (M ) 3. Easy for the receiver to decrypt ciphertect using private key: M = DKRb (C) = DKRb[EKUb (M )] Henric Johnson 4 Requirements for Public-Key Cryptography 4. Computationally infeasible to determine private key (KRb) knowing public key (KUb) 5. Computationally infeasible to recover message M, knowing KUb and ciphertext C 6. Either of the two keys can be used for encryption, with the other used for decryption: M = DKRb[EKUb (M )] = DKUb[EKRb (M )] Henric Johnson 5 Public-Key Cryptographic Algorithms ! RSA and Diffie-Hellman ! RSA - Ron Rives, Adi Shamir and Len Adleman at MIT, in 1977. • RSA -
A Password-Based Key Derivation Algorithm Using the KBRP Method
American Journal of Applied Sciences 5 (7): 777-782, 2008 ISSN 1546-9239 © 2008 Science Publications A Password-Based Key Derivation Algorithm Using the KBRP Method 1Shakir M. Hussain and 2Hussein Al-Bahadili 1Faculty of CSIT, Applied Science University, P.O. Box 22, Amman 11931, Jordan 2Faculty of Information Systems and Technology, Arab Academy for Banking and Financial Sciences, P.O. Box 13190, Amman 11942, Jordan Abstract: This study presents a new efficient password-based strong key derivation algorithm using the key based random permutation the KBRP method. The algorithm consists of five steps, the first three steps are similar to those formed the KBRP method. The last two steps are added to derive a key and to ensure that the derived key has all the characteristics of a strong key. In order to demonstrate the efficiency of the algorithm, a number of keys are derived using various passwords of different content and length. The features of the derived keys show a good agreement with all characteristics of strong keys. In addition, they are compared with features of keys generated using the WLAN strong key generator v2.2 by Warewolf Labs. Key words: Key derivation, key generation, strong key, random permutation, Key Based Random Permutation (KBRP), key authentication, password authentication, key exchange INTRODUCTION • The key size must be long enough so that it can not Key derivation is the process of generating one or be easily broken more keys for cryptography and authentication, where a • The key should have the highest possible entropy key is a sequence of characters that controls the process (close to unity) [1,2] of a cryptographic or authentication algorithm . -
Authentication and Key Distribution in Computer Networks and Distributed Systems
13 Authentication and key distribution in computer networks and distributed systems Rolf Oppliger University of Berne Institute for Computer Science and Applied Mathematics {JAM) Neubruckstrasse 10, CH-3012 Bern Phone +41 31 631 89 51, Fax +41 31 631 39 65, [email protected] Abstract Authentication and key distribution systems are used in computer networks and dis tributed systems to provide security services at the application layer. There are several authentication and key distribution systems currently available, and this paper focuses on Kerberos (OSF DCE), NetSP, SPX, TESS and SESAME. The systems are outlined and reviewed with special regard to the security services they offer, the cryptographic techniques they use, their conformance to international standards, and their availability and exportability. Keywords Authentication, key distribution, Kerberos, NetSP, SPX, TESS, SESAME 1 INTRODUCTION Authentication and key distribution systems are used in computer networks and dis tributed systems to provide security services at the application layer. There are several authentication and key distribution systems currently available, and this paper focuses on Kerberos (OSF DCE), NetSP, SPX, TESS and SESAME. The systems are outlined and reviewed with special regard to the security services they offer, the cryptographic techniques they use, their conformance to international standards, and their availability and exportability. It is assumed that the reader of this paper is familiar with the funda mentals of cryptography, and the use of cryptographic techniques in computer networks and distributed systems (Oppliger, 1992 and Schneier, 1994). The following notation is used in this paper: • Capital letters are used to refer to principals (users, clients and servers). -
TRANSPORT LAYER SECURITY (TLS) Lokesh Phani Bodavula
TRANSPORT LAYER SECURITY (TLS) Lokesh Phani Bodavula October 2015 Abstract 1 Introduction The security of Electronic commerce is completely in the hands of Cryptogra- phy. Most of the transactions through e-commerce sites, auction sites, on-line banking, stock trading and many more are exchanged over the network. SSL or TLS are the additional layers that are required in order to obtain authen- tication, privacy and integrity for all kinds of communication going through network. This paper focuses on the additional layer (TLS) which is responsi- ble for the whole communication. Transport Layer Security is a protocol that is responsible for offering privacy between the communicating applications and their users on Internet. TLS is inserted between the application layer and the network layer-where the session layer is in the OSI model TLS, however, requires a reliable transport channel-typically TCP. 2 History Instead of the end-to-end argument and the S-HTTP proposal the developers at Netscape Communications introduced an interesting secured connection concept of low-layer and high-layer security. For achieving this type of security there em- ployed a new intermediate layer between the transport layer and the application layer which is called as Secure Sockets Layer (SSL). SSL is the starting stage for the evolution of different transport layer security protocols. Technically SSL protocol is assigned to the transport layer because of its functionality is deeply inter-winded with the one of a transport layer protocol like TCP. Coming to history of Transport layer protocols as soon as the National Center for Super- computing Application (NCSA) released the first popular Web browser called Mosaic 1.0 in 1993, Netscape Communications started working on SSL protocol. -
True Random Number Generators Secure in a Changing Environment
True Random Number Generators Secure in a Changing Environment Boaz Barak, Ronen Shaltiel, and Eran Tromer Department of Computer Science and Applied Mathematics Weizmann Institute of Science , Rehovot, ISRAEL Email: {boaz,ronens,tromer}@wisdom.weizmann.ac.il Abstract. A true random number generator (TRNG) usually consists of two components: an “unpredictable” source with high entropy, and a randomness extractor — a function which, when applied to the source, produces a result that is statistically close to the uniform distribution. When the output of a TRNG is used for cryptographic needs, it is pru- dent to assume that an adversary may have some (limited) influence on the distribution of the high-entropy source. In this work: 1. We define a mathematical model for the adversary’s influence on the source. 2. We show a simple and efficient randomness extractor and prove that it works for all sources of sufficiently high-entropy, even if individual bits in the source are correlated. 3. Security is guaranteed even if an adversary has (bounded) influence on the source. Our approach is based on a related notion of “randomness extraction” which emerged in complexity theory. We stress that the statistical ran- domness of our extractor’s output is proven, and is not based on any unproven assumptions, such as the security of cryptographic hash func- tions. A sample implementation of our extractor and additional details can be found at a dedicated web page [Web]. 1 Introduction 1.1 General setting It is well known that randomness is essential for cryptography. Cryptographic schemes are usually designed under the assumption of availability of an endless stream of unbiased and uncorrelated random bits. -
An Efficient Watermarking and Key Generation Technique Using DWT Algorithm in Three- Dimensional Image
International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-8 Issue-2, July 2019 An Efficient Watermarking and Key Generation Technique Using DWT Algorithm in Three- Dimensional Image R. Saikumar, D. Napoleon Abstract:Discrete Wavelet Transform is the algorithm which obtained by compressive sensing. It is a novel technology can be used to increase the contrast of an image for better visual used to compress the data at a higher rate than the quality of an image. The histogram value for original image with highest bins is taken for embedding the data into an image to conventional method. The compression and encryption are perform the histogram equalization for repeating the process achieved by a single linear measurement step through a simultaneously. Information can be embedded into the source measurement matrix, which can be generated by the secret image with some bit value, for recovering the original image key. This key can be shared only among the sender and the without any loss of the pixels. DWT is the first algorithm which has achieved the image contrast enhancement accurately. This receiver at the time of sending and receiving data as a approach maintained the original visual quality of an image even multimedia file. though themessage bits are embedded into the contrast-enhanced images. The proposed work with an original watermarking II. LITERATURE REVIEW scheme based on the least significant bit technique. As a substitute of embedding the data into a simple image as Y. Sridhar et al: An author says about the unique structure watermarking, least significant bitmethod by utilizing the three about the scalable coding for PRNG images which have wavelets transform is applied in the proposed system in order to been encrypted. -
Data Encryption Standard (DES)
6 Data Encryption Standard (DES) Objectives In this chapter, we discuss the Data Encryption Standard (DES), the modern symmetric-key block cipher. The following are our main objectives for this chapter: + To review a short history of DES + To defi ne the basic structure of DES + To describe the details of building elements of DES + To describe the round keys generation process + To analyze DES he emphasis is on how DES uses a Feistel cipher to achieve confusion and diffusion of bits from the Tplaintext to the ciphertext. 6.1 INTRODUCTION The Data Encryption Standard (DES) is a symmetric-key block cipher published by the National Institute of Standards and Technology (NIST). 6.1.1 History In 1973, NIST published a request for proposals for a national symmetric-key cryptosystem. A proposal from IBM, a modifi cation of a project called Lucifer, was accepted as DES. DES was published in the Federal Register in March 1975 as a draft of the Federal Information Processing Standard (FIPS). After the publication, the draft was criticized severely for two reasons. First, critics questioned the small key length (only 56 bits), which could make the cipher vulnerable to brute-force attack. Second, critics were concerned about some hidden design behind the internal structure of DES. They were suspicious that some part of the structure (the S-boxes) may have some hidden trapdoor that would allow the National Security Agency (NSA) to decrypt the messages without the need for the key. Later IBM designers mentioned that the internal structure was designed to prevent differential cryptanalysis. -
Extracting Randomness from Extractor-Dependent Sources
Extracting Randomness from Extractor-Dependent Sources Yevgeniy Dodi Vinod Vaikuntanathan NYU MIT Daniel Wichs Northeastern University and NTT Research Inc. February 19, 2020 Abstract We revisit the well-studied problem of extracting nearly uniform randomness from an arbi- trary source of sufficient min-entropy. Strong seeded extractors solve this problem by relying on a public random seed, which is unknown to the source. Here, we consider a setting where the seed is reused over time and the source may depend on prior calls to the extractor with the same seed. Can we still extract nearly uniform randomness? In more detail, we assume the seed is chosen randomly, but the source can make arbitrary oracle queries to the extractor with the given seed before outputting a sample. We require that the sample has entropy and differs from any of the previously queried values. The extracted output should look uniform even to a distinguisher that gets the seed. We consider two variants of the problem, depending on whether the source only outputs the sample, or whether it can also output some correlated public auxiliary information that preserves the sample’s entropy. Our results are: Without Auxiliary Information: We show that every pseudo-random function (PRF) with a sufficiently high security level is a good extractor in this setting, even if the distin- guisher is computationally unbounded. We further show that the source necessarily needs to be computationally bounded and that such extractors imply one-way functions. With Auxiliary Information: We construct secure extractors in this setting, as long as both the source and the distinguisher are computationally bounded. -
CCAM an Intelligence Brute Force Attack on RSA Cryptosystem
Communications in Computational and Applied Mathematics, Vol. 1 No. 1 (2019) p. 1-7 CCAM Communications in Computational and Applied Mathematics Journal homepage : www.fazpublishing.com/ccam e-ISSN : 2682-7468 An Intelligence Brute Force Attack on RSA Cryptosystem Chu Jiann Mok1, Chai Wen Chuah1,* 1Information Security Interest Group (ISIG), Faculty of Computer Science and Information Technology, Universiti Tun Hussein Onn Malaysia 86400 Parit Raja, Batu Pahat, MALAYSIA *Corresponding Author Received 27 November 2018; Abstract: RSA cryptosystem is the one of the public key cryptosystem used for secure data Accepted 01 March 2019; transmission. In this research, an intelligence brute force attack is proposed for attacking RSA Available online 07 March cryptosystem cryptanalysis. In the paper, the effectiveness in cryptanalysis is simulated. An 2019 experimental analysis of the proposed approach is carried out in order to evaluate its effectiveness in terms of time used for recovery RSA key. Performance of proposed algorithm compared with prime factorization and brute force attack on RSA toy box. The results are used to estimate the time required for real-life RSA cryptosystem in ideal conditions. Keywords: RSA cryptosystem, public key cryptosystem, brute force, cryptanalysis 1. Introduction Table 1 - Relationship between number of bits used in RSA was invented by Ron Rivest, Adi Shame and RSA cryptosystem and prime-to-nature numbers ratio Leonard Adleman in 1977. RSA is a public key cryptosystem Maximum nature No. Prime Prime-to- for securing data transmission. RSA encryption is asymmetric number numbers nature cipher, which consists of two keys: public key (,)ne and numbers ratio private key (,,)pqd . -
A Simple Secret Key Generation by Using a Combination of Pre-Processing Method with a Multilevel Quantization
entropy Article A Simple Secret Key Generation by Using a Combination of Pre-Processing Method with a Multilevel Quantization Mike Yuliana 1,2,* , Wirawan 1 and Suwadi 1 1 Department of Electrical Engineering, Faculty of Electrical Technology, Institut Teknologi Sepuluh Nopember, Jalan Raya ITS, Keputih, Sukolilo, Surabaya 60111, Indonesia; [email protected] (W.); [email protected] (S.) 2 Department of Electrical Engineering, Politeknik Elektronika Negeri Surabaya (PENS), Jalan Raya ITS, Keputih, Sukolilo, Surabaya 60111, Indonesia * Correspondence: [email protected] or [email protected]; Tel.: +62-812-1746-4666 Received: 14 January 2019; Accepted: 15 February 2019; Published: 18 February 2019 Abstract: Limitations of the computational and energy capabilities of IoT devices provide new challenges in securing communication between devices. Physical layer security (PHYSEC) is one of the solutions that can be used to solve the communication security challenges. In this paper, we conducted an investigation on PHYSEC which utilizes channel reciprocity in generating a secret key, commonly known as secret key generation (SKG) schemes. Our research focused on the efforts to get a simple SKG scheme by eliminating the information reconciliation stage so as to reduce the high computational and communication cost. We exploited the pre-processing method by proposing a modified Kalman (MK) and performing a combination of the method with a multilevel quantization, i.e., combined multilevel quantization (CMQ). Our approach produces a simple SKG scheme for its significant increase in reciprocity so that an identical secret key between two legitimate users can be obtained without going through the information reconciliation stage. -
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TLS Specification for Storage Systems Version 2.0 ABSTRACT: This document specifies the requirements and guidance for use of the Transport Layer Security (TLS) protocol in conjunction with data storage technologies. The requirements are intended to facilitate secure interoperability of storage clients and servers as well as non-storage technologies that may have similar interoperability needs. This document was developed with the expectation that future versions of SMI-S and CDMI could leverage these requirements to ensure consistency between these standards as well as to more rapidly adjust the security functionality in these standards. This document has been released and approved by the SNIA. The SNIA believes that the ideas, methodologies and technologies described in this document accurately represent the SNIA goals and are appropriate for widespread distribution. Suggestions for revisions should be directed to https://www.snia.org/feedback/. SNIA Standard February 1, 2021 USAGE The SNIA hereby grants permission for individuals to use this document for personal use only, and for corporations and other business entities to use this document for internal use only (including internal copying, distribution, and display) provided that: 1. Any text, diagram, chart, table or definition reproduced shall be reproduced in its entirety with no alteration, and, 2. Any document, printed or electronic, in which material from this document (or any portion hereof) is reproduced shall acknowledge the SNIA copyright on that material, and shall credit the SNIA for granting permission for its reuse. Other than as explicitly provided above, you may not make any commercial use of this document, sell any or this entire document, or distribute this document to third parties. -
Human Assisted Randomness Generation Using Video Games
Human Assisted Randomness Generation Using Video Games Mohsen Alimomeni, Reihaneh Safavi-Naini University of Calgary, Department of Computer Science malimome,[email protected] January 19, 2014 Abstract Random number generators have direct applications in information security, online gaming, gambling, and computer science in general. True random number generators need an entropy source which is a physical source with inherent uncertainty, to ensure unpredictability of the output. In this paper we propose a new indirect approach to collecting entropy using human errors in the game play of a user against a computer. We argue that these errors are due to a large set of factors and provide a good source of randomness. To show the viability of this proposal, we design and implement a game, conduct a user study in which we collect user input in the game, and extract randomness from it. We measure the rate and the quality of the resulting randomness that clearly show effectiveness of the approach. Our work opens a new direction for construction of entropy sources that can be incorporated into a large class of video games. 1 Introduction Randomness has a central role in computer science and in particular information security. Security of cryptographic algorithms and protocols relies on keys that must be random. Random coins used in randomized encryption and authentication algorithms and values such as nonces in protocols, must be unpredictable. In all these cases, unpredictability of random values is crucial for security proofs. There are also applications such as online games, gambling applications and lotteries in which unpredictability is a critical requirement.