Multiple E-mail address certificate

Digital signature certificates are digitally signed identity certificates issued by trusted Certification Authorities (CA´s) to individuals, devices, applications, or services. E-mail Certificates (EC´s) are issued primarily for the purpose of signing and encrypting e-mail messages. E-mail clients use sender´s E-mail Certificate (Private Key) for signing and recipient´s E-mail Certificate (Public Key) for encrypting an e-mail message. This paper proposes inclusion of multiple e-mail addresses in E-mail Certificates and puts forward modified procedure to allow e-mail clients to use a single E-mail Certificate of an individual for different e-mail addresses to sign and encrypt e-mail messages. Further, it discusses generation of multiple e-mail address certificates and demonstrates their working using an e-mail client developed for the said purpose.