We have beautiful technology called MD5 Hash for banning files, then why file hosting sites never implement this thing on DMCA files?
closed as off-topic by Neil Smithline, Matthew, Ohnana, tim, Rory Alsop♦ May 12 '16 at 18:17
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "This question does not appear to be about Information security within the scope defined in the help center." – Neil Smithline, Matthew, Ohnana, tim, Rory Alsop
Because every version of a protected file would have to have their MD5 hash submitted, and a pirate can alter the file (add or remove something) and thereby modify the hash.
Hashes are the wrong technology to do what you are thinking. Hashes are good for claiming that 2 files are the same, not that all files must be the same file.