Is CRC32 so bad for checking file integrity?

Question

Of course, MD5 is better than CRC32, SHA1 is better than MD5, etc. But they are also much slower than CRC32.

I know correctly, I’m thinking about how to check the consistency of the transferred file, and CRC32 is the fastest option.

I have not found anywhere how bad CRC32 is for integrity checking (maybe, in other words, how probably CRC32 does not detect a malformed file)?

Answer 1

Quote from http://www.mathpages.com/home/kmath458.htm :

, , , , , , , 1/(2 ^ n). , 16- CRC 1/(2 ^ 16) = 1.5E-5 - , 32- CRC 1/(2 ^ 32), 2.3E-10 ( ).

: CRC-32 . . , "-".

Answer 2

( , ) CRC-32, CRC-32 32 ex. MD5 - 128 , SHA-1 - 160 , SHA-2 (SHA256/512 series) - 224 -512 . ( , ). , SHA-2 .

, . , Hash Collision