Can I prevent duplicate content using md5?

Question

I would like to prevent duplication of content. I do not want to keep copies of the content, so I decided to keep only the md5 signatures.

I read that md5 collision is happening, different contents can give in the same md5 signature.

Do you think md5 is enough?

Should I use md5 and sh1 together?

Answer 1

People were able to deliberately make MD5 collisions in far-fetched conditions, but to prevent duplication of content (in the absence of malicious users) this is more than adequate.

, SHA-1 ( SHA-2), - , .

Answer 2

MD5 , , , sha-1.

, , , , . , .

Answer 3

, -? - , . , , .

Answer 4

md5 . , , , , , , .

Answer 5

, MD5 SHA1 . , . , .

Answer 6

, .

MD5 , . MD5-, , MD5, CSR RapidSSL , . ! 179 .

SHA , , . .

Answer 7

MD5 SHA1 . SHA2.

Based on an update from the OP, it seems that intentional collisions here are not a serious problem. For the unintended, any decent hash with at least 64-bit output would be fine.

I would still have avoided MD5 and even SHA1 in general, but there is no reason to be dogmatic. If the tool fits here, then of course use it.

Answer 8

The timestamp + md5 together is quite safe.