We investigate the structure and cryptographic applications of the Discrete Lambert Map (DLM), the mapping x 7→ xgxmod p, for p a prime and some fixed g ∈ (Z/pZ)∗. The mapping is closely related to the Discrete Log Problem, but has received far less attention since it is considered to be a more complicated map that is likely even harder to invert. However, this mapping is quite important becaus...

We introduce a new cryptographic technique that we call universal re-encryption. A conventional cryptosystem that permits reencryption, such as ElGamal, does so only for a player with knowledge of the public key corresponding to a given ciphertext. In contrast, universal re-encryption can be done without knowledge of public keys. We propose an asymmetric cryptosystem with universal re-encryptio...

We propose a concept for a worldwide information security infrastructure that protects law-abiding citizens, but not criminals, even if the latter use it fraudulently (i.e. when not complying with the agreed rules). It can be seen as a middle course between the inflexible but fraudresistant KMI-proposal [8] and the flexible but non-fraud-resistant concept used in TIS-CKE [2]. Our concept consis...

Application of digital signature technology becomes more extensive, but many exposed digital signature algorithms have increasingly revealed some shortcomings and deficiencies. Aiming directly at the frequently used digital signature technologies, which are weak to Substitution Attack and Homeostasis Attack, the authors perform the hash transformation on messages before signature. Then, a hash ...

An On-chip Data Storage with cryptosystem proposed in this paper was designed for modern smart card system and “on the fly data encryption/decryption”. To ensure the security, the ElGamal Elliptic curve cryptosystems with the key size of 176 bits was embeded. The design can be configured to be either the encrypter or the decryptor with simple control signals. To minimize the hardware cost, size...

In this paper, we consider what condition is sufficient for random inputs to secure probabilistic public-key encryption schemes. Although a framework given in [16] enables us to discuss uniformly and comprehensively security notions of public-key encryption schemes even for the case where cryptographically weak pseudorandom generator is used as random nonce generator to encrypt single plaintext...

In asynchronous wireless sensor networks it is not possible to transmit the monitored data to an authorized recipient in real-time. Thus, the data needs to be stored within the network in distributed fashion. However, due to the resource constraints of the sensor nodes the amount of data to be stored and transmitted must be minimized. One popular technique for this is in-network data aggregatio...

We present algorithms for digital signature generation and verification using public key cryptography over an arbitrary group G. The algorithms are similar to those of ElGamal, but do not require a knowledge of the group order. Forging signatures or determining the secret key requires the solution of a discrete logarithm problem over G, or the solution of other problems which appear at least as...