PGP Protocol and Its Applications
Hilal M. Yousif Al-Bayatti, Abdul Monem S. Rahma, Hala Bahjat Abdul Wahab · InTech eBooks · 2012
Key management cryptographic systems Conventional encryptionConventional encryption has benefits; most notably speed.It is especially useful for encrypting data which will not be transmitted.However, conventional encryption alone, as a means for transmitting secure data, can be expensive simply due to the difficulty of secure key distribution (Droste, 1996).For a sender and recipient to communicate securely using conventional encryption, they must agree upon a key and keep it secret between themselves.If they are in different physical locations, they must trust a courier or some other secure communications medium to prevent the disclosure of the secret key during transmission (Sauer & Chandy, 1981). Public-key cryptographyThe concept of public-key cryptography was introduced in 1976 by Whitfield Diffie and Martin Hellman and, independently, by Ralph Markle, to solve the key management problem in secret-key cryptography.Each person receives a pair of different but related www.intechopen.comCryptography and Security in Computing 182 keys; the public-key and the private key (Schneir, 1996).The public key is published, while the private key is kept secret.Anyone can send a confidential message