# Divertible Protocols and Atomic Proxy Cryptography

@inproceedings{Blaze1998DivertiblePA, title={Divertible Protocols and Atomic Proxy Cryptography}, author={Matt Blaze and Gerrit Bleumer and Martin Strauss}, booktitle={EUROCRYPT}, year={1998} }

First, we introduce the notion of divertibility as a protocol property as opposed to the existing notion as a language property (see Okamoto, Ohta [OO90. [...] Key Method Next, we introduce atomic proxy cryptography, in which an atomic proxy function, in conjunction with a public proxy key, converts ciphertexts (messages or signatures) for one key into ciphertexts for another. Proxy keys, once generated, may be made public and proxy functions applied in untrusted environments. Expand

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#### References

SHOWING 1-10 OF 25 REFERENCES

On Protocol Divertibility

- Computer Science
- IACR Cryptol. ePrint Arch.
- 1998

A definition of protocol divertibility is given that applies to arbitrary 2-party protocols and is compatible with Okamoto and Ohta’s definition in the case of interactive zero-knowledge proofs. Expand

Any Language in IP Has a Divertable ZKIP

- Computer Science
- ASIACRYPT
- 1991

There exists a perfectly divertible perfect zero-knowledge interactive proof system for graph non-isomorphism (GNI) without any unproven assumption. Expand

A method for obtaining digital signatures and public-key cryptosystems

- Computer Science
- CACM
- 1978

An encryption method is presented with the novel property that publicly revealing an encryption key does not thereby reveal the corresponding decryption key, soriers or other secure means are not needed to transmit keys. Expand

An Improved Protocol for Demonstrating Possession of Discrete Logarithms and Some Generalizations

- Mathematics, Computer Science
- EUROCRYPT
- 1987

It is proved that the sequential versions of these protocols do not reveal any "knowledge" about the discrete logarithm(s) in a well-defined sense, provided that A knows (a multiple of) the order of α. Expand

Yvo Desmedt: All Languages in NP Have Divertible Zero-Knowledge Proofs and Arguments Under Cryptographic Assumptions

- Computer Science
- EUROCRYPT
- 1990

A divertible zero-knowledge proof for graph isomorphism is presented under the assumption that probabilistic encryption homomorphisms exist and the consequences for abuse-free zero- knowledge proofs are considered. Expand

Meta-Message Recovery and Meta-Blind Signature Schemes Based on the Discrete Logarithm Problem and Their Applications

- Computer Science
- ASIACRYPT
- 1994

This paper presents the Meta-blind signature schemes which have been developed from the ElGamal based blind signature scheme and the message recoveryblind signature scheme discovered recently, and extracts various variants from which some are more efficient than the already known ones. Expand

Divertible Zero Knowledge Interactive Proofs and Commutative Random Self-Reducibility

- Mathematics, Computer Science
- EUROCRYPT
- 1989

It is shown that any commutative random self-reducible problem, which is a variant of the randomSelfReduction problem introduced by Angluin et al., has a divertible perfect zero knowledge interactive proof. Expand

How to Prove Yourself: Practical Solutions to Identification and Signature Problems

- Computer Science
- CRYPTO
- 1986

Simple identification and signature schemes which enable any user to prove his identity and the authenticity of his messages to any other user without shared or public keys are described. Expand

A public key cryptosystem and a signature scheme based on discrete logarithms

- Computer Science
- IEEE Trans. Inf. Theory
- 1985

A new signature scheme is proposed, together with an implementation of the Diffie-Hellman key distribution scheme that achieves a public key cryptosystem that relies on the difficulty of computing discrete logarithms over finite fields. Expand

New directions in cryptography

- Computer Science
- IEEE Trans. Inf. Theory
- 1976

This paper suggests ways to solve currently open problems in cryptography, and discusses how the theories of communication and computation are beginning to provide the tools to solve cryptographic problems of long standing. Expand