No, if you have a 128 bit block and a 16 bit check code, you'll get the same check code for approximately 2**(128-16) blocks (aka 2**112).
CRC codes
Aug 03, 2012
23 Replies
[Snipped by Lyons]
Hello Poncho, I haven't read this complete thread. But remember, if someone does build a reliable CRC system, they didn't build that. Some one else made that happen.
[-Rick-]
I was under the impression that CRCs are generally designed and used to detect errors, for example in packets sent over the Internet ...
I was looking for strong evidence that advanced error-correcting codes were used in hard drives.
Hitachi produces enterprise-class hard-drives, which tend to pack more GB per square inch, spin faster and have lower error rates.
From this piece from 2008, one learns that they produced dense packing based in part on LDPC codes (low-density parity check codes):
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> .
More recently, they've done production od drives that use
LDPC codes:
From the spec. document for Deskstar 5K3000 & Ultrastar 5K3000
hard disk drives:
"576 bit LDPC in 512 byte format"
Early tape drives used longitudinal and vertical parity bits for error checking. AFAIK the first use of a CRC was in data communications during the mid 1960's.
Shmuel (Seymour J.) Metz, SysProg and JOAT
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