A Hybrid Security Algorithm AES and Blowfish for Authentication in Mobile Applications
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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 -
Report on the AES Candidates
Rep ort on the AES Candidates 1 2 1 3 Olivier Baudron , Henri Gilb ert , Louis Granb oulan , Helena Handschuh , 4 1 5 1 Antoine Joux , Phong Nguyen ,Fabrice Noilhan ,David Pointcheval , 1 1 1 1 Thomas Pornin , Guillaume Poupard , Jacques Stern , and Serge Vaudenay 1 Ecole Normale Sup erieure { CNRS 2 France Telecom 3 Gemplus { ENST 4 SCSSI 5 Universit e d'Orsay { LRI Contact e-mail: [email protected] Abstract This do cument rep orts the activities of the AES working group organized at the Ecole Normale Sup erieure. Several candidates are evaluated. In particular we outline some weaknesses in the designs of some candidates. We mainly discuss selection criteria b etween the can- didates, and make case-by-case comments. We nally recommend the selection of Mars, RC6, Serp ent, ... and DFC. As the rep ort is b eing nalized, we also added some new preliminary cryptanalysis on RC6 and Crypton in the App endix which are not considered in the main b o dy of the rep ort. Designing the encryption standard of the rst twentyyears of the twenty rst century is a challenging task: we need to predict p ossible future technologies, and wehavetotake unknown future attacks in account. Following the AES pro cess initiated by NIST, we organized an op en working group at the Ecole Normale Sup erieure. This group met two hours a week to review the AES candidates. The present do cument rep orts its results. Another task of this group was to up date the DFC candidate submitted by CNRS [16, 17] and to answer questions which had b een omitted in previous 1 rep orts on DFC. -
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 -
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. -
Access Control Model with Attribute Based Multiple Encryption
International Journal for Research in Engineering Application & Management (IJREAM) ISSN : 2454-9150 Vol-03, Issue 01, Apr 2017 Access Control Model with Attribute Based Multiple Encryption 1Aishwarya Shinde, 2Rupali Kangane, 3Priyanka Deshmukh, 4Mr. Satish L. Kuchiwale 1,2,3UG Student, 4Professor, 1,2,3,4S.I.G.C.E, Mumbai, Maharashtra, India. [email protected], [email protected], [email protected], [email protected] Abstract — Users are provided by an online storage space hosted on drobox, accessible anywhere via the Internet. Hierarchical Attributed Set Based Encryption (HASBE) concept used in existing system. User is responsible for keeping the data available and accessible but issues arises such as time complexity, flexibility, data security, scalability. These issues are solved in developed system with the help of Cipher Text-Policy attribute-set-based Encryption (CP-ABE). It is an access control model where data will be stored in encrypted form on drobox and data will decrypted using keys. In developed system, multiple encryption is done using four different algorithms named as AES, Blowfish, RSA and Triple DES. These algorithms are used for images, doc and pdf files etc. Furthermore, integrating all these algorithms with CP-ABE key generation techniques used for encrypting file. When compared to existing system, developed system provides data security with less time complexity. Keywords — Scalability, Flexibility, Attribute, Cipher text-policy. I. INTRODUCTION1 security depends on more than simply applying appropriate data security procedures. Computer based security measures Cryptography is a technique for securing the secrecy of mostly capitalizes on user authorization and authentication. communication and many different methods have been HASBE(Hierarchical Attributed Set Based developed to encrypt and decrypt data in order to keep the Encryption)scheme is not scalable and flexible for key message secret. -
Miss in the Middle Attacks on IDEA and Khufu
Miss in the Middle Attacks on IDEA and Khufu Eli Biham? Alex Biryukov?? Adi Shamir??? Abstract. In a recent paper we developed a new cryptanalytic techni- que based on impossible differentials, and used it to attack the Skipjack encryption algorithm reduced from 32 to 31 rounds. In this paper we describe the application of this technique to the block ciphers IDEA and Khufu. In both cases the new attacks cover more rounds than the best currently known attacks. This demonstrates the power of the new cryptanalytic technique, shows that it is applicable to a larger class of cryptosystems, and develops new technical tools for applying it in new situations. 1 Introduction In [5,17] a new cryptanalytic technique based on impossible differentials was proposed, and its application to Skipjack [28] and DEAL [17] was described. In this paper we apply this technique to the IDEA and Khufu cryptosystems. Our new attacks are much more efficient and cover more rounds than the best previously known attacks on these ciphers. The main idea behind these new attacks is a bit counter-intuitive. Unlike tra- ditional differential and linear cryptanalysis which predict and detect statistical events of highest possible probability, our new approach is to search for events that never happen. Such impossible events are then used to distinguish the ci- pher from a random permutation, or to perform key elimination (a candidate key is obviously wrong if it leads to an impossible event). The fact that impossible events can be useful in cryptanalysis is an old idea (for example, some of the attacks on Enigma were based on the observation that letters can not be encrypted to themselves). -
Comparative Analysis of Advanced Encryption Standard, Blowfish and Rivest Cipher 4 Algorithms
www.ijird.com November, 2014 Vol 3 Issue 11 ISSN 2278 – 0211 (Online) Comparative Analysis of Advanced Encryption Standard, Blowfish and Rivest Cipher 4 Algorithms Adolf Fenyi Researcher, Kwame Nkrumah University of Science and Technology, Knust, Ghana Joseph G. Davis Lecturer, Kwame Nkrumah University of Science and Technology, Knust, Ghana Dr. Kwabena Riverson Head of Programme CSIR Institute of Industrial Research Accra, Ghana Abstract: Cryptography is one of the main categories of computer security that converts information from its normal form into an unreadable form. The two main characteristics that identify and differentiate one encryption algorithm from another are its ability to secure the protected data against attacks and its speed and efficiency in doing so.Cryptography is required to transmit confidential information over the network. It is also demanding in wide range of applications which includes mobile and networking applications. Cryptographic algorithms play a vital role in providing the data security against malicious attacks. But on the other hand, they consume significant amount of computing resources like CPU time, memory, encryption time etc. Normally, symmetric key algorithms are preferred over asymmetric key algorithms as they are very fast in nature. Symmetric algorithms are classified as block cipher and stream ciphers algorithms. In this research project, I comparedthe AES and Blowfish algorithms with different modes of operation (ECB, CBC, and CFB) and RC4 algorithm (stream cipher) in terms encryption time, decryption time, memory utilization and throughput at different settings likevariable key size and variable data packet size.A stimulation program is developed using PHP and JavaScript scripting languages. The program encrypts and decrypts different file sizes ranging from 1MB to 50MB. -
AES, Blowfish and Twofish for Security of Wireless Networks
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 07 Issue: 06 | June 2020 www.irjet.net p-ISSN: 2395-0072 Comparison of Encryption Algorithms: AES, Blowfish and Twofish for Security of Wireless Networks Archisman Ghosh Department of Computer Science & Engineering, National Institute of Technology, Durgapur, West Bengal, India --------------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Encryption is the process of encoding data to A secure WiFi system uses algorithms such as DES, RSA, prevent unauthorized access. Cyber security is the need of AES, Blowfish and Twofish to secure the communication the hour which ensures transfer of data across the internet over seemingly unsecured Internet channels. In addition, with confidentiality and integrity, and provides protection the existing cryptographic algorithm is based on an against malicious attacks. In this research paper, encryption model designed by Horst Feistel of IBM [4]. comparison between the encryption algorithms, viz. AES (Advanced Encryption Standard), Blowfish, and Twofish is In this paper, a comparative study of the cryptographic done in terms of time of encryption and decryption, and algorithms: AES, Blowfish and Twofish has been done and their throughput, and the results are analysed indicating the the results have been analysed in order to find the superiority of Twofish over AES and Blowfish as a viable algorithm most suitable for encrypting data in wireless algorithm for data encryption in wireless networks. networks. Keywords: Cryptography, Network security, AES, 2. Overview of the algorithms Blowfish, Twofish, Secure communication. 2.1 AES 1. Introduction The Advanced Encryption Standard (AES) is a Owing to the advancement in internet accessibility and cryptographic algorithm for encryption of electronic data networking, most of the security sensitive stuff like established by the U.S. -
A New Stream Cipher HC-256
A New Stream Cipher HC-256 Hongjun Wu Institute for Infocomm Research 21 Heng Mui Keng Terrace, Singapore 119613 [email protected] Abstract. Stream cipher HC-256 is proposed in this paper. It generates keystream from a 256-bit secret key and a 256-bit initialization vector. HC-256 consists of two secret tables, each one with 1024 32-bit elements. The two tables are used as S-Box alternatively. At each step one element of a table is updated and one 32-bit output is generated. The encryption speed of the C implementation of HC-256 is about 1.9 bit per clock cycle (4.2 clock cycle per byte) on the Intel Pentium 4 processor. 1 Introduction Stream ciphers are used for shared-key encryption. The modern software efficient stream ciphers can run 4-to-5 times faster than block ciphers. However, very few efficient and secure stream ciphers have been published. Even the most widely used stream cipher RC4 [25] has several weaknesses [14, 16, 22, 9, 10, 17, 21]. In the recent NESSIE project all the six stream cipher submissions cannot meet the stringent security requirements [23]. In this paper we aim to design a very simple, secure, software-efficient and freely-available stream cipher. HC-256 is the stream cipher we proposed in this paper. It consists of two secret tables, each one with 1024 32-bit elements. At each step we update one element of a table with non-linear feedback function. Every 2048 steps all the elements of the two tables are updated. -
CMCC: Misuse Resistant Authenticated Encryption with Minimal Ciphertext Expansion
cryptography Article CMCC: Misuse Resistant Authenticated Encryption with Minimal Ciphertext Expansion Jonathan Trostle Independent Researcher, Washington, DC 98684, USA; [email protected] or [email protected]; Tel.: +1-360-253-8417 Received: 21 September 2018; Accepted: 4 December 2018; Published: 19 December 2018 Abstract: In some wireless environments, minimizing the size of messages is paramount due to the resulting significant energy savings. We present CMCC (CBC-MAC-CTR-CBC), an authenticated encryption scheme with associated data (AEAD) that is also nonce misuse resistant. The main focus for this work is minimizing ciphertext expansion, especially for short messages including plaintext lengths less than the underlying block cipher length (e.g., 16 bytes). For many existing AEAD schemes, a successful forgery leads directly to a loss of confidentiality. For CMCC, changes to the ciphertext randomize the resulting plaintext, thus forgeries do not necessarily result in a loss of confidentiality which allows us to reduce the length of the authentication tag. For protocols that send short messages, our scheme is similar to Synthetic Initialization Vector (SIV) mode for computational overhead but has much smaller expansion. We prove both a misuse resistant authenticated encryption (MRAE) security bound and an authenticated encryption (AE) security bound for CMCC. We also present a variation of CMCC, CWM (CMCC With MAC), which provides a further strengthening of the security bounds. Keywords: energy constrained cryptography; authenticated encryption; misuse resistance 1. Introduction The current paradigm of providing confidentiality and integrity protection for distributed applications through the use of encryption combined with MAC’s (Message Authentication Codes) is reasonably efficient for many environments. -
AES3 Presentation
Cryptanalytic Progress: Lessons for AES John Kelsey1, Niels Ferguson1, Bruce Schneier1, and Mike Stay2 1 Counterpane Internet Security, Inc., 3031 Tisch Way, 100 Plaza East, San Jose, CA 95128, USA 2 AccessData Corp., 2500 N University Ave. Ste. 200, Provo, UT 84606, USA 1 Introduction The cryptanalytic community is currently evaluating five finalist algorithms for the AES. Within the next year, one or more ciphers will be chosen. In this note, we argue caution in selecting a finalist with a small security margin. Known attacks continuously improve over time, and it is impossible to predict future cryptanalytic advances. If an AES algorithm chosen today is to be encrypting data twenty years from now (that may need to stay secure for another twenty years after that), it needs to be a very conservative algorithm. In this paper, we review cryptanalytic progress against three well-regarded block ciphers and discuss the development of new cryptanalytic tools against these ciphers over time. This review illustrates how cryptanalytic progress erodes a cipher’s security margin. While predicting such progress in the future is clearly not possible, we claim that assuming that no such progress can or will occur is dangerous. Our three examples are DES, IDEA, and RC5. These three ciphers have fundamentally different structures and were designed by entirely different groups. They have been analyzed by many researchers using many different techniques. More to the point, each cipher has led to the development of new cryptanalytic techniques that not only have been applied to that cipher, but also to others. 2 DES DES was developed by IBM in the early 1970s, and standardized made into a standard by NBS (the predecessor of NIST) [NBS77].