RSA and Bell Labs 2, 3] have recently announced a potential attack on certain public key protocols, along with several suggested countermeasures. The most secure of these countermeasures uses the concept of plaintext aware, which means that it should be infeasible to construct a valid ciphertext without knowing the corresponding plaintext. Failure to be plaintext aware may open a cryptosystem t...

A distributed E-Business System based on conic curve is proposed. This scheme is composed of two parts, constructing license and validating license. Because the security of license is determined by private key, not the arithmetic itself, user can not construct new license by given license and the public key as long as the private key is not leaked. Since encoding and decoding over conic are eas...

In this paper a new structural attack on the McEliece/Niederreiter public key cryptosystem based on subcodes of generalized ReedSolomon codes proposed by Berger and Loidreau is described. It allows the reconstruction of the private key for almost all practical parameter choices in polynomial time with high probability.

Time-sensitive mobile commerce is vulnerable to message authentication delays. Significant power consumption incurred by cryptography is another limiting factor of most mobile devices. In this paper, we present a scalable mobile cryptosystem, which installs a group key and an elliptic curve private/public key pair in each device to enable both symmetric key and public key cryptography. We propo...

Both systems are public key systems, meaning that there is a secret key used for decryption and a publicly available key used for encrypting. In theory everyone can send you an encrypted message by using the public key (if they know where to obtain it), but you’re the only one who can decrypt the message. Of course these systems rely on the difficulties in obtaining the private key, when knowin...

We improve our proposal of a new variant of the McEliece cryptosystem based on QC-LDPC codes. The original McEliece cryptosystem, based on Goppa codes, is still unbroken up to now, but has two major drawbacks: long key and low transmission rate. Our variant is based on QC-LDPC codes and is able to overcome such drawbacks, while avoiding the known attacks. Recently, however, a new attack has bee...

A multi-dimensional QTRU public-key cryptosystem improves NTRU by replacing the original ring in quaternion algebra. In this paper, we introduce QMNTR an improvement of using a new mathematical structure two public keys and five private keys. This modification has enhanced key system to be more robust secure.

A new public key cryptosystem, called REESSE1+, was proposed. REESSE1 consists of two primitive algorithms, a public key encryptio/decryption algorithm and a digital signature algorithm. We give some analysis to REESSE1+, and show that the system is totally unsecure. We show how to derive the private key from the public key. As the same time, we also show how to forge signatures for any message...

Identity-Based Encryption is a public key cryptosystem that uses the receiver identifier information such as email address, IP name and etc, to compute private in encrypt message. A message can obtain secret corresponding with his privacy from Private Key Generator he decrypt ciphertext. In this paper, we review Boneh-Franklin’s scheme use bilinear map Weil pairing’s properties propose an ident...

We propose a one-round 1-out-of-n computationally-private information retrieval protocol for `-bit strings with low-degree polylogarithmic receivercomputation, linear sender-computation and communication Θ(k · log n + ` · log n), where k is a possibly non-constant security parameter. The new protocol is receiver-private if the underlying length-flexible additively homomorphic public-key cryptos...