Bitcoin Forum

Other => Off-topic => Topic started by: ndnh on February 04, 2015, 10:53:14 AM



Title: Reading about hashing - SHA
Post by: ndnh on February 04, 2015, 10:53:14 AM
I was reading about this. Just went curious how it works and why it is practically impossible to decrypt.

But while reading it, i got the impression that multiple messages can have the same hash? though the probability must be very low. Is it possible?


Title: Re: Reading about hashing - SHA
Post by: Balthazar on February 04, 2015, 11:11:35 AM
Just went curious how it works and why it is practically impossible to decrypt.
Hashing != encryption.

http://www.youtube.com/watch?v=y3dqhixzGVo

But while reading it, i got the impression that multiple messages can have the same hash? though the probability must be very low. Is it possible?
Yes, of course. That's inevitable if message is longer than hash value.


Title: Re: Reading about hashing - SHA
Post by: ndnh on February 04, 2015, 11:23:52 AM
Just went curious how it works and why it is practically impossible to decrypt.
Hashing != encryption.

http://www.youtube.com/watch?v=y3dqhixzGVo

But while reading it, i got the impression that multiple messages can have the same hash? though the probability must be very low. Is it possible?
Yes, of course. That's inevitable if message is longer than hash value.

lol, I just replaced the word with decrypt personally haven't heard of "dehashing" much, so I substituted another word with almost similar meaning. Intention was only to make someone who read understand.


If it gets repeated, isn't the chance of that happenning very slim? Is it possible to calculate another message, if the hash is given and the real message is known, that has the same hash without much difficulty?


Title: Re: Reading about hashing - SHA
Post by: b!z on February 04, 2015, 07:54:11 PM
Just went curious how it works and why it is practically impossible to decrypt.
Hashing != encryption.

http://www.youtube.com/watch?v=y3dqhixzGVo

But while reading it, i got the impression that multiple messages can have the same hash? though the probability must be very low. Is it possible?
Yes, of course. That's inevitable if message is longer than hash value.

lol, I just replaced the word with decrypt personally haven't heard of "dehashing" much, so I substituted another word with almost similar meaning. Intention was only to make someone who read understand.


If it gets repeated, isn't the chance of that happenning very slim? Is it possible to calculate another message, if the hash is given and the real message is known, that has the same hash without much difficulty?

Google "SHA-___ collision"