Reversing a hash

[Yehuda25]

I have a hashed mac address, and the mac address (the key) is there any way using this info to find out the hash that was used to hash it originally?

[AnonymousUser]

I have a hashed mac address, and the mac address (the key) is there any way using this info to find out the hash that was used to hash it originally?

Unless you know the algorithm that was used, I think that's the whole point of a hash, that it cannot be used to figure out the data it came from.

[BAHayman]

A hash is a one way function and cannot be reversed.

If you have the data that was hashed, and it wasn't salted, or hashed with a key using an hmac, then you can at least narrow it down by the length of the hash.

The most common hashes are md5, sha1, and the sha2 family. You can check Wikipedia for the length of the hashes. http://en.m.wikipedia.org/wiki/List_of_hash_functions

It would only take a couple of minutes to rehash the data and see if you get the same result.

[Yehuda25]

A hash is a one way function and cannot be reversed.

If you have the data that was hashed, and it wasn't salted, or hashed with a key using an hmac, then you can at least narrow it down by the length of the hash.

The most common hashes are md5, sha1, and the sha2 family. You can check Wikipedia for the length of the hashes. http://en.m.wikipedia.org/wiki/List_of_hash_functions

It would only take a couple of minutes to rehash the data and see if you get the same result.

thank you! I'm going to give it a try now!

[satturn]

i think this is the first time a did not understand a single word of a DD thread.... And i'm the techie type

[whYME]

i think this is the first time a did not understand a single word of a DD thread.... And i'm the techie type

FTR, this this whole thread is essentially a repost 
http://forums.dansdeals.com/index.php?topic=6618.msg172543#msg172543

[AnonymousUser]

FTR, this this whole thread is essentially a repost 
http://forums.dansdeals.com/index.php?topic=6618.msg172543#msg172543

As is 65% of DDF.

[Yehuda25]

FTR, this this whole thread is essentially a repost 
http://forums.dansdeals.com/index.php?topic=6618.msg172543#msg172543

Not really, this is trying to reconstruct the hash, that thread is mostly concerning the strength of the hashes in regard to whether they were salted or not. Similar concept though.