Fast Implementation of Digital Signatures Using Parallel Techniques

Digital signatures are widely used to check the authenticity of the identity of the signatory of the message/document and the integrity of the message sent. They are also used by the receiver for ensuring non-repudiation by the sender. They play an important role in making day-to-day processes electronic and paperless. Digital signatures are based on public key infrastructure (PKI). The message digest (hash) of the file is signed by the sender using a private key and appended to the file. The recipient extracts the signature, decrypting it with the sender's public key, and verifies if the received digest matches its own hash calculations. However, complex calculations for secure signatures imply that digital signatures are time consuming for large files. Hashing is the basic security mechanism used in digital signatures that is performed by all the parties and consumes most of the time. This paper presents a solution to this problem by using parallel hashing to achieve fast digital signatures, discussing two possible approaches. The first one uses only parallel hashing, keeping the rest of the algorithm the same as the reference algorithm based on RSA. The second approach parallelizes the entire reference algorithm. Both were implemented using the OpenMP framework, and the experimental results show a significant decline in the execution time in both the cases.