This paper is intended to provide a cloud-based digital signature platform with biometric authentication and establishes an enhanced security solution in the field of cryptography. We proposed a new schema of digital signature where signature generation and verification is done on the cloud environment. Like Public Key Infrastructure each user owned a pair of key - private key and public key. A signer has to confirm his biometric identification (vein pattern) and a one-time key verification to access the private key for signing a document. This one-time key (OTK) is only shared between the signer and the receiver additionally they use it for a single document signing or verification. Before the verification of a signature or a document, a receiver also needs to prove his identity using his vein pattern. To complete the verification process, he/she must provide the public key of the signer and the shared one-time key to the system. Thus our system gives a confidential interaction between the signer and the receiver of the document.