Abstract
A ciphertext-policy attribute-based encryption system, comprising a re-encrypter (9) for cryptographically transforming a first ciphertext (CTp1) associated with a first access policy (P1) into a second ciphertext (CTP2) associated with a second access policy (P2) by means of a re-encryption key (RK). The system further comprises a re-encryption key generator (7) for generating the re-encryption key (RK), wherein the re-encryption key (RK) enables the re-encrypter (9) to cryptographically transform the first ciphertext (CTP1) associated with the first access policy (P1) into the second ciphertext (CTP2) associated with the second access policy (P2). Said re-encryption key generator (7) comprises a subsystem for encrypting a value derived from a pseudorandom number, thereby generating a further ciphertext associated with the second access policy (P2).
| Original language | Undefined |
|---|---|
| Patent number | WO2010IB54581 |
| Priority date | 11/10/10 |
| Publication status | Submitted - 11 Oct 2010 |
Keywords
- EWI-20947
- Encryption
- METIS-281623
- IR-78966
- Attribute
- Ciphertext