Security of signed ELGamal encryption
- Assuming a cryptographically strong cyclic group G of prime order q and a random hash function H, we show that ElGamal encryption with an added Schnorr signature is secure against the adaptive chosen ciphertext attack, in which an attacker can freely use a decryption oracle except for the target ciphertext. We also prove security against the novel one-more-decyption attack. Our security proofs are in a new model, corresponding to a combination of two previously introduced models, the Random Oracle model and the Generic model. The security extends to the distributed threshold version of the scheme. Moreover, we propose a very practical scheme for private information retrieval that is based on blind decryption of ElGamal ciphertexts.
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| Author: | Claus Peter SchnorrGND, Markus Jakobsson |
|---|---|
| URN: | urn:nbn:de:hebis:30-12257 |
| ISBN: | 3-540-41404-5 |
| Publisher: | Springer |
| Place of publication: | Berlin [u.a.] |
| Document Type: | Preprint |
| Language: | English |
| Date of Publication (online): | 2005/07/12 |
| Year of first Publication: | 2000 |
| Publishing Institution: | Universitätsbibliothek Johann Christian Senckenberg |
| Release Date: | 2005/07/12 |
| Page Number: | 16 |
| First Page: | 73 |
| Last Page: | 89 |
| Note: | Preprint, später in: Advances in cryptology, 2000, Lecture notes in computer science, Vol. 1976, S. 73-89 |
| Source: | Lecture notes in computer science, Vol. 1976 |
| HeBIS-PPN: | 358646499 |
| Institutes: | Informatik und Mathematik / Mathematik |
| Informatik und Mathematik / Informatik | |
| Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 51 Mathematik / 510 Mathematik |
| Licence (German): |  Deutsches Urheberrecht |
