A New Fair Identity Based Encryption Scheme

In 1984, Shamir presented the first Identity Based cryptography scheme resolving the public key sharing using signatures. Identity Based Encryption (IBE) remained an open problem for many years. Boneh and Franklin or Cocks presented some IBE schemes. IBE scheme was improved by Malek with a sender authentication in addition to the encryption. We improve this solution by solving the key escrow problem. The trusted center has access on a partial private key in our solution. This method allows to guarantee the data confidentiality between the sender and the recipient. Even if an attacker retrieves the master key of the trusted center, the data confidentiality is guaranteed for the previous and next exchanges.