What is the current number of web sites?

In this case, the standard C function rand, which is a pseudo-random number generator, is seeded using the C time function. According to the ANSI C standard, time returns a value of type time t, which is implementation defined, but most commonly a 32-bit integer containing the current number of seconds since January 1, 1970 (see: Unix time). There are about 31 million seconds in a year, so an attacker who knows the year in which the password was generated (a simple matter in situations where frequent password changes are mandated by password policy) faces a relatively small number, by cryptographic standards, of choices to test. In situations where the attacker can obtain an encrypted version of the password, such testing can be performed rapidly enough so that a few million trial passwords can be checked in a matter of seconds. See: password cracking.