A multi-prime RSA with enhanced bit-stuffing for securing email messages

Abstract

Electronic mail has become the most widely used communication system worldwide, due to the various benefits attached, like speed, conveniences to transmit messages. Security threats are the constant issues with electronic mail messages which due to the fact that current email protocols SMTP (Simple Mail Transfer Protocol), POP (Post Office Protocol) and IMAP (Internet Mail Access Protocol) send and store email messages in plaintext on the email server. Recently, Email security protocol were developed such as Pretty Good Protocol (PGP)and Secure Multi–purpose Internet Mail Extension Protocol (S/MIME) to secure email content end to end, but with several limitations such as expensive certificate management, key management problems which result to low adoptability of these protocols. These security lapses made the email server to be targeted by most attackers, also passwords as authentication techniques are very weak. This paper presents an encryption algorithm for securing email application. The encryption techniques include a well-known RSA algorithm (multiple prime numbers) with enhanced bit insertion techniques with the goals to improve security of lower key length of RSA, computational time of RSA and enhancing email message security.