Factoring
is the act of splitting an integer into a set of smaller integers, called factors, which when multiplied together form the original integer. Prime factorization requires that the factors are prime numbers. It is assumed that factoring numbers with very large prime factors is very difficult. Many public key cryptosystems, such as RSA, are based on this assumption.
Fansubing
is the act to add subtitles on illegal movies.
FEAL (Fast Data Encipherment Algorithm)
is a 64-bit block cipher with a 64-bit key. It was presented as an alternative to DES. It is considered to be insecure.
Firewall
Component or set of components that restricts access between a protected network and an open network (e.g. the Internet)
First Virtual & trade
is one of the earliest card-based payment system launched in Oct. 1994 by a company called First Virtual Holdings, Inc. It allowed selling low-value information items across the Internet.
Forward secrecy
is the characteristic of a secure protocol using session key. Forward secrecy ensures that the compromise of the current session key does not allow to compromise earlier session keys.