Breaking the Akiyama-Goto cryptosystem

A public key cryptosystem based on diophantine equations of degree increasing type

In this paper we propose a new public key cryptosystem based on diophantine equations which we call of degree increasing type. We use an analogous method to the “Algebraic Surface Cryptosystem” (ASC) proposed by Akiyama, Goto and Miyake. There are two main differences between our cryptosystem and ASC. One of them is to twist a plaintext by using some modular arithmetic to increase the number of...

Practical Cryptanalysis of a Public-Key Encryption Scheme Based on Non-linear Indeterminate Equations at SAC 2017

We investigate the security of a public-key encryption scheme, the Indeterminate Equation Cryptosystem (IEC), introduced by Akiyama, Goto, Okumura, Takagi, Nuida, and Hanaoka at SAC 2017 as postquantum cryptography. They gave two parameter sets PS1 (n, p, deg X, q) = (80, 3, 1, 921601) and PS2 (n, p, deg X, q) = (80, 3, 2, 58982400019). The paper gives practical key-recovery and message-recover...

A Public-key Encryption Scheme Based on Non-linear Indeterminate Equations (Giophantus)

In this paper, we propose a post-quantum public-key encryption scheme whose security depends on a problem arising from a multivariate non-linear indeterminate equation. The security of lattice cryptosystems, which are considered to be the most promising candidate for a post-quantum cryptosystem, is based on the shortest vector problem or the closest vector problem in the discrete linear solutio...

LinkDB: A Database of Cross Links between Molecular Biology Databases

Improving the Rao-Nam secret key cryptosystem using regular EDF-QC-LDPC codes

This paper proposes an efficient joint secret key encryption-channel coding cryptosystem, based on regular Extended Difference Family Quasi-Cyclic Low-Density Parity-Check codes. The key length of the proposed cryptosystem decreases up to 85 percent using a new efficient compression algorithm. Cryptanalytic methods show that the improved cryptosystem has a significant security advantage over Ra...