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Confused on verification speed

Posted: 27 Oct 2011 17:00
by pissant
Regarding the verification option during file copies, the help file says:
Byte-to-byte: Most secure, but slower on huge files.

· MD5: Fastest of the hashing algorithms offered here.

· SHA-1: More secure than MD5 but slightly slower. Faster than Byte-to-byte on huge files.
To perform a byte-to-byte comparison, of course, the entire file must be read (both copies). But each entire file must also be read before performing either MD5 or SHA-1 hashing. So my question becomes: Is Byte-to-byte slower not because of storage medium I/O but because of the processor-intensive comparison process, which is actually more intensive than hashing?

Re: Confused on verification speed

Posted: 27 Oct 2011 17:18
by admin
Good question. MD5 uses the Windows Crypto API which seems to know a trick that I don't know. Hence it does the bigger job slightly faster than I do the smaller job. I'm embarrassed but can't help it at the moment.