New approach of user authentication using digital signature

Digital signature is a keyword used to define the authentication of the data. It is used to ensure that information is not updated during the transmission. An authentication service makes sure that a communication is authentic and the message is from the source that it claims to be from. In this paper, we define a method that uses another signer as a proxy to sign the documents. A proxy signature scheme provides the ability to the sender to delegate it's signing ability to another signer. We describe a new protected proxy signature scheme that provides protection to proxy signer private key. This scheme uses a certificate that holds identity of signer, delegation duration, and imposes rules on the signing ability delegated by the original signer. Therefore, a proxy can sign the document instead of the signer in the validity period.