The Elliptic Curve Digital Signature Algorithm (ECDSA) consists of two modules: one is the signing algorithm used by a signer and the second one is the verification algorithm used by public to verify the signer's identity. A person who wants to sign a message digitally uses the signing algorithm, which first makes a message digest (hash) of the message using a suitable hash function (SHA-1) and then the message digest is encrypted using the signer's private key. The encrypted message digest is the "Digital Signature" of the sender on that message. Anyone can verify whether that "Digital Signature" is authentic or not by using verification algorithm. At first a message digest of the signer's message is created using the identical hash function (SHA-1). The verifier then decrypts the ciphered hash output using the signer's public key. If the ciphered hash output and the message digest created by the verifier are found to be identical, the signer's authenticity is proved. During theperiod of project duration, a java application program has been written in which the ECDSA functionality of both signing and verification is provided.