A digital signature is used to sign and encrypt documents which need to upload
for bidding at time of bid submission and decrepit documents tender opening time at
officer end. It is basically an encrypted hash of the message. The recipient
can check if the message was tampered with by hashing the received message and
comparing this value with the decrypted signature.
To decrypt the signature, the corresponding public key is
required. A digital certificate is
used to bind public keys to persons or other entities. If there were no
certificates, the signature could be easily be forged, as the recipient could
not check if the public key belongs to the sender.
As per Section 18 of The Information Technology Act, 2000 provides the required legal sanctity to the digital signatures based on asymmetric cryptograms.The IT Act provides for the Controller of Certifying Authorities(CCA) to license and regulate the working of Certifying Authorities. The Certifying Authorities (CAs) issue digital signature certificates for electronic authentication of users. Certificate Authority like n-(code).