2.25: news.cyb/dev/sec/git uses SHA-1 deprecated by NIST in 2011:
. git allows teams to concurrently work on software;
it uses SHA-1 hashing of versions,
to tell when files of a version have been modified
to help it merge versions of the software.
. SHA-1 has been cracked so you can modify a file
and yet have it result in the same SHA-1 hash,
thereby hiding the fact that it has been modified.
. the leader of git would like to replace SHA-1
with a more secure hash using more bits,
but would like to use a truncated version of that hash
so that git would only have to store and compare
the same number of bits as SHA-1.
. git is assumed by the leader of git, Linus Torvalds,
to be less vulnerable to the SHA-1 attack
because it includes not just the hash of a file
but also its size;
he gives no proof other than appeal to intuition:
can you imagine a way to add working malware to a file
while also keeping both the hash and the size the same?