Library routines
CRC-CCITT functions
CRC16 functions
<*> CRC32 functions
CRC32c (Castagnoli, et al) Cyclic Redundancy-Check

I'm compiling a new kernel 2.6.16.11. I've read the help for this functions. So I know that they are provided for the case where no in-kernel-tree modules require CRC-CCITT functions, but a module built outside the kernel tree does. and they are also used in checking for errors in data transmission. CRC error checking uses a complex polynomial to generate a number based on the data transmitted. The sending device performs the calculation before transmission and sends its result to the receiving device. The receiving device repeats the same calculation after transmission. If both devices obtain the same result, it is assumed that the transmission was error-free. The procedure is known as a redundancy check because each transmission includes not only data but extra (redundant) error-checking values."
that's ok.
Does anybody can tell me in simply words what this mean. i didn't study informatics so I don't know if I need them in my kernel or not. And what are they in practice used for in my PC?
the same situation comes with "Security options"
Thanx