Years ago it used to be the case that Unix passwords were limited to 8 characters, or that if you made the password longer than 8 characters the extra wouldn\'t make any differe
Are you asking about the crypt
algorithm?
http://linux.die.net/man/3/crypt
"By taking the lowest 7 bits of each of the first eight characters of the key..."
"The glibc2 version of this function has the following additional features. ... The entire key is significant here (instead of only the first 8 bytes)."
Here's a hint as to how long ago this change happened.
Glibc 2 HOWTO
Eric Green, ejg3@cornell.edu
v1.6, 22 June 1998