| 摘要 |
Identifier-Based Encryption (IBE) is an emerging cryptographic schema, according to which a data provider encrypts payload data using both an encryption key string, and public data provided by a trusted authority. In the invention, a method and apparatus is provided using IBE for securely transferring first and second data (43,42) from a user (39) to first and second parties (35,38) respectively. More particularly, the user (39) encrypts the first data (43) using a first encryption key (40) associated with the first party (35), and then encrypts the second data (42) using, as encryption parameters, both public data (37) of the first party (35) and third data (44) comprising the encrypted first data. The third data (44) is then provided, preferably via the second party (38), to the first party (35), and the encrypted second data (45) is provided to the second party (38). The first party (35) uses a first decryption key to decrypt the encrypted first data, as provided to the first party in the third data (44), whereby to recover the first data (43). The first party also uses the third data (44), along with private data related to the aforesaid public data, to generate a second decryption key (47) which is then provided to the second party (38) to enable it to decrypt the encrypted second data (45). <IMAGE> |
