A Key Escrow Free Anonymous Identity Based Encryption Scheme using Ring Signatures

Identity-based encryption (IBE) is an encryption scheme that is proposed to eliminate the need for certificates to certify the public keys of receivers in public-key cryptography (PKC). Nevertheless, the key escrow problem is a major problem to deploy identity-based encryption (IBE) in real-time. If the private key generator (PKG) is malicious, then he can decrypt all the messages. In this paper, we proposed an anonymous identity-based encryption scheme using ring signatures to solve this problem. In this process, the identity will get the corresponding private key from the key generation authority (KGA) by signing on masked identity using the ring signature generated by ring authority (RA). The KGA has no way of knowing who received which key. Hence, it solves the key escrow problem. While most existing techniques require certificates to ensure anonymity, which is also a motive for IBE, the proposed scheme will obtain the relevant key anonymously based on the ring signatures. In this paper, a proof of security of the proposed scheme is also presented along with the scheme.