Cloud computing provides services where one can access information from any place, from anywhere, at any time. So basically cloud computing is subscription based service where one can obtain network storage space and computer resources for data storage as well as data sharing. Due to high fame of cloud for data storage and sharing, a large number of participants gets attracted to it. The security is the biggest concern for the adoption of the cloud. The major issues in this regard are efficiency, data integrity, privacy, and authentication. In order to handle these issues concept of a ring, the signature has been introduced for data sharing amongst a large number of users. Ring signatures are used to provide user’s anonymity and signer’s privacy. But the expensive certificate verification within the ancient Public Key Infrastructure (PKI) setting becomes a bottleneck for this solution to be scalable. ID-based ring signature had been introduced which eliminates the process of certificate verification. Further enhancement of security with forwarding security concept has been introduced. According to this idea, if a secret key of any user has been compromised; all previously generated signatures that embrace this user still stay valid. This property is very vital to any giant scale knowledge sharing system because it is not possible to raise all knowledge data owners to re-authenticate their data whether or not a secret key of 1 single user has been compromised. Thus we propose a secure ID-based ring signature with forwarding security.