Ciphering/Encryption

In RHEL 5.2 we can see SHA-1 being used for the ciphering/encryption. It produces 160 bit digest from a message of width max length: (2^64-1) and based on the principles of MD4, MD5 message digest algorithms.

http://en.wikipedia.org/wiki/Sha1

To view the installed cryptographic ciphers in Linux

#cat /proc/crypto
name : crc32c
driver : crc32c-generic
module : kernel
priority : 0
type : digest
blocksize : 32
digestsize : 4

name : sha1
driver : sha1-generic
module : kernel
priority : 0
type : digest
blocksize : 64
digestsize : 20