Threshold cryptosystems

Abstract

Abstract.In a society oriented cryptography it is better to have a public key for the company (organization) than having one for each individual employee [.es88]. Certainly in emergency situations, power is shared in many organizations.Solutions to this problem were presented [.e.s88], based on [GMW87], but are completely impractical and intemctive. In this paper practical non-intemctiue public key systems are proposed which allow the reuse of the shared secret key since the key is not revealed either to insiders or to outsiders.

How to Construct Multicast Cryptosystems Provably Secure Against Adaptive Chosen Ciphertext Attack

“…Threshold cryptosystems are part of a general approach known as threshold cryptography, introduced by Boyd [28], Desmedt [29], and Desmedt and Frankel [30]. There are schemes based on both Diffie-Hellman problem [30] and RSA [31].…”

“…There are schemes based on both Diffie-Hellman problem [30] and RSA [31]. All these schemes can be shown to be secure against chosen plaintext attack, but they are not known to withstand chosen ciphertext attack.…”

Chosen Ciphertext Secure Public Key Threshold Encryption Without Random Oracles

“…A threshold public key encryption system [14,16,13,19] is a public key system where the private key is distributed among n decryption servers so that at least k servers are needed for decryption. In a threshold encryption system an entity, called the combiner, has a ciphertext C that it wishes to decrypt.…”

Threshold Cryptography Based on Asmuth-Bloom Secret Sharing

“…A function sharing scheme (FSS) requires distributing the function's computation according to the underlying SSS such that each part of the computation can be carried out by a different user and then the partial results can be combined to yield the function's value without disclosing the individual secrets. Several protocols for function sharing [6,[8][9][10][11]16,24,26] have been proposed in the literature. Nearly all existing solutions for function sharing have been based on the Shamir SSS [25].…”