Abstract: Identity-based ring signature has wide applications such as ad-hoc networks etc., since it can protect the privacy of signer and simplify the process of key management. However, most of existing schemes are constructed from bilinear pairings. In this paper, we firstly propose a new identity-based ring signature scheme based on cubic residues. Our proposed scheme is secure against existential forgery on the adaptively chosen identity and message attacks under the random oracle model assuming the hardness of factoring. Our work extends the research field of identity-based ring signature due to the new mathematical tools.