Security and Privacy Issues in Secure E-Mail Standards and Services

One of the most popular Internet services is e-mail services which provide sending and receiving electronic messages of communication networks. E-mail standards and services apply various cryptographic algorithms to achieve the security goals (Stallings, 2006; Stallings, 2007) of confidentiality, integrity, authentication and non-repudiation. Data confidentiality in e-mail services is commonly made available via cryptographic encryption. Since symmetric key ciphers, such as DES, Triple-DES and AES, process data at higher rates than public key ciphers, such as RSA, they are ABSTRACT