More and more software use cryptography. But how can one know if what is implemented is good cryptography? For proprietary software, one cannot say much unless one proceeds to reverse-engineering, and history tends to show that bad cryptography is much more frequent than good cryptography there. Open source software thus sounds like a good solution, but the fact that a source code can be read d...

Elliptic curve cryptosystems, proposed by Koblitz([8]) and Miller([11]), can be constructed over a smaller definition field than the ElGamal cryptosystems([5]) or the RSA cryptosystems([16]). This is why elliptic curve cryptosystems have begun to attract notice. There are mainly two types in elliptic curve cryptosystems, elliptic curves E over IF2r and E over IFp. Some current systems based on ...

This paper proposes a chosen-ciphertext secure variant of the ElGamal public-key encryption scheme which generates very compact ciphertexts for messages of arbitrary length. The ciphertext overhead (i.e., the difference between ciphertext and plaintext) is one group element only. Such a property is particularly useful when encrypting short messages such as a PIN or a credit card number in bandw...

In the paper, we propose a new digital signature scheme based on factoring and discrete logarithms. Specially, we prove that the security of the proposed signature scheme is based on both the security of the ElGamal signature scheme and the security of the modified OSS signature scheme. This is the first scheme which can be proved that its security is based on two hard problems. Like Meta-ElGam...

Data aggregation is a popular approach employed in wireless sensor networks (WSNs) to minimize data transmission and storage. With aggregation techniques, the monitored data is expressed in a condensed form: Therefore, instead of storing all data sensed by several nodes, the network stores a condensed value only such as the sum of these values. However, data aggregation becomes problematic when...

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