A secure cryptosystem based on affine transformation

Abstract

In this paper, it is proved that Lin et al.'s scheme that tried to strengthen the Hill cipher against the known-plaintext attack has several security flaws and is vulnerable to the chosen-ciphertext attack. This paper also introduces a secure and efficient symmetric cryptosystem based on affine transformation. The proposed cryptosystem includes an encryption algorithm that is an improved variant of the Affine Hill cipher, and two cryptographic protocols that are introduced for the proposed cryptosystem.devoted to Lin et al.'s scheme [9] and its cryptanalysis. The proposed cryptosystem and its attributes, including evaluation of its computational costs is presented in Section 4. A key generation algorithm for the proposed cryptosystem is described in Section 5 and Section 6 concludes the paper.

Cryptanalysis of the Toorani-Falahati Hill Ciphers

“…Toorani and Falahati introduce TFHC2 in [10], together with a two-pass protocol ("Protocol A") and a one-pass protocol ("Protocol B"). The core cipher is identical to TFHC1, except for the technique used to generate the a t value for each plaintext.…”

“…In 2009 and 2011, Toorani and Falahati introduced two variants of the Hill Cipher, together with protocols for the exchange of encrypted messages [9,10]. We refer to these ciphers as TooraniFalahati Hill Cipher #1 (2009) and #2 (2011), and we shorten the names to TFHC1 and TFHC2.…”

A hill cipher‐based remote data possession checking in cloud storage

“…If it happens that this system is indeterminate, it is necessary to add a few more plaintext/ciphertext pairs. Fortunately, there are some researches on improving the security of Hill cipher . Security analysis of the scheme The security of the scheme depends on the data encryption key K , the secret key ks , and the verifiable tags, namely the confidentiality of the sum of the product of the file blocks.…”

“…As Hill cipher is secure only to ciphertext attacks, the scheme is secure in this case. Moreover, there are some researches on improving the security of Hill cipher .…”

“…If it happens that this system is indeterminate, it is necessary to add a few more plaintext/ ciphertext pairs. Fortunately, there are some researches on improving the security of Hill cipher [24][25][26][27][28][29].…”