Goldwasser and Kharchenko (TCC 2006) showed a proof of plaintext knowledge for the AjtaiDwork cryptosystem and left the open problem designing a proof of plaintext knowledge for the Regev’04 cryptosystem (JACM 2004). In this paper, we show a proof of plaintext knowledge for the Regev’04 cryptosystem (JACM 2004) using their technique. Furthermore, we show that it can be applied to the Regev’05 c...

Braid cryptosystem was proposed in CRYPTO 2000 as an alternate public-key cryptosystem. The security of this system is based upon the conjugacy problem in braid groups. Since then, there have been several attempts to break the braid cryptosystem by solving the conjugacy problem in braid groups. In this paper, we first survey all the major attacks on the braid cryptosystem and conclude that the ...

RSA cryptosystem, the first public key cryptography presented in 1977. Neural networks are often used as a powerful discriminating estimator for tasks in function approximation. This paper describes a neural-network-based method relies on Radial Basis Function and Levenberg-Marquardt Backpropagation for estimating the behavior of the function used in RSA cryptosystem to calculate the function. ...

The HKM / HFX cryptosystem is proposed for standardization at the ITU Telecommunication Standardization Sector Study Group 8. It is designed to provide authenticity and colffidentiality of FAX messages at a commercial level of security. In addition, the HKM / HFX cryptosystem is designed for unrestricted export. This paper contains the results of an analysis of the HKM/HFX cryptosystem. Eleven ...

In 1984, Shamir [1] introduced the concept of an identity-based cryptosystem. In this system, each user needs to visit a key authentication center (KAC) and identify him self before joining a communication network. Once a user is accepted, the KAC will provide him with a secret key. In this way, if a user wants to communicate with others, he only needs to know the “identity” of his communicatio...

XTR is one of the most efficient public-key cryptosystems that allow us to compress the communication bandwidth of their ciphertext. The compact representation can be achieved by deploying a subgroup Fq2 of extension field Fq6 , so that the compression ratio of XTR cryptosystem is 1/3. On the other hand, Dijk et al. proposed an efficient public-key cryptosystem using a torus over Fq30 whose com...

Throughout the history of cryptography, hundreds of cryptosystems have been developed. The earliest ones, as well as many later ones, relied on the complete secrecy in transferring keys between the sender and recipient. These kinds of systems, called secret key cryptosystem, have just a single key which is used for both encryption and decryption; therefore, these systems are more frequently kno...

The need of exchanging messages and images secretly over unsecure networks promoted the creation of cryptosystems to enable receivers to interpret the exchanged information. In this paper, a particular public key cryptosystem called the ElGamal Cryptosystem is presented considered with the help MATLAB Program to be used over Images. Since the ElGamal cryptosystem over a primitive root of a larg...

The asymmetric cryptosystem plays an important role in the cryptology nowadays. It is widely used in the fields of data encryption, digital watermarking, digital signature, secure network protocol, etc. However, with the improvement of computing capability, longer and longer the key length is required to ensure the security of interaction information. To shorten the key length and improve the e...