DAFA - A Lightweight DES Augmented Finite Automaton Cryptosystem

Abstract

Abstract. Unlike most cryptosystems which rely on number theoretic problems, cryptosystems based on the invertibility of finite automata are lightweight in nature and can be implemented easily using simple logical operations, thus affording fast encryption and decryption. In this paper, we propose and implement a new variant of finite automaton cryptosystem, which we call DES-Augmented Finite Automaton (DAFA) cryptosystem. DAFA uses the key generation algorithm of the Data Encryption Standard (DES) to dynamically generate linear and non-linear finite automata on the fly using a 128-bit key. Compared to existing finite automaton cryptosystems, DAFA provides stronger security yet has similar encryption/decryption speeds. DAFA is also faster than popular single key cryptosystems such as Advanced Encryption Standard (AES). The test results on desktop and mobile phones with respect to the running speed and security properties are very promising.

Application of Decimated Mathematical Equations and Polynomial Root-Finding Method in Protection of Text Messages

“…Consequently, the key space exceeds 2 256 bits. This is substantial enough to thwart brute-force attempts [32,33], and it is larger than the key size of the pseudorandom output algorithms proposed in [9,11,19,[34][35][36][37].…”

FSAaCIT: Finite State Automata based One-Key Cryptosystem and Chunk-based Indexing Technique for Secure Data De-duplication in Cloud Computing

“…The process of retrieving input sequence with the knowledge of current state and past output history is called finite-memory state automata of order k. Where k -is the least integer that determines the current state of automata with knowledge of last k output sequence and generates k input sequence 12,17,18 . These both process is known as (h, k) − order memory FSA.…”

“…Data confidentiality is achieved by FSA based encryption algorithm A that has smaller keyspace but provides better security ( 11,14 ) due to its invertibility concept. Because conventional cryptosystem uses the concept of logarithmic and bilinear pairing that consumes more computational resources which leads to the computational overhead on C Adopt and CSS.…”

“…The adversary can perform dictionary attack by guessing or trying all possible keys to decrypt C text . Since P text is encrypted by FSA based encryption A that provides better security ( 11,21,22,23,24,25 ) due to its invertibility concept. The adversaries need to identify decryption key A −1 to decrypt the ciphertext.…”

“…Therefore, we propose finite state automata (FSA) based client-side encryption technique and server-side hash-based indexing technique to accomplish secure data outsourcing to prevent the issues aforesaid. The FSA based cryptosystem is very light-weight in nature due to its linear invirtability concept and provide better security 11 . The paper also provide PoW and DIV protocol to fight against unauthorized access and modification of confidential data stored in the cloud storage server (CSS).…”