sha1sum: Print or check SHA-1 digests
sha1sum computes a 160-bit checksum for each specified
file. The usage and options of this command are precisely the
same as for
md5sum. See md5sum invocation.
Note: The SHA-1 digest is more reliable than a simple CRC (provided by
cksum command) for detecting accidental file corruption,
as the chances of accidentally having two files with identical SHA-1
are vanishingly small. However, it should not be considered secure
against malicious tampering: although finding a file with a given SHA-1
fingerprint is considered infeasible at the moment, it is known how
to modify certain files, including digital certificates, so that they
appear valid when signed with an SHA-1 digest. For more secure hashes,
consider using SHA-2, or the newer
See sha2 utilities. See b2sum invocation.