Can anyone help me to decrypt this...

[EmPowerYou]

I think it is coded with sha1, but i'm not that sure, so if theres anyone who can help, i'll be glad!
Here's the hash:
0DF3F69A90331668B1B2510B5FCA4C8FE7EE5E9E

[limdis]

Where did it come from?

[wan26]

More information would be nice.

[EmPowerYou]

Well a friend of mine said that its impossible to decrypt the hash, so we had a bet. I tried the popular sites for decrypting and the Cain app, but nothing... So what do you think, is it encrypted with sha1 or what?

[LoGiCaL__]

Hashes are made to be irreversible. The only way to find out what it would be is to compare values to their hashed values. So if you know what kind of hash it is you can try to perform a dictionary attack or use rainbow tables.

[RiptideTempora]

Well a friend of mine said that its impossible to decrypt the hash, so we had a bet. I tried the popular sites for decrypting and the Cain app, but nothing... So what do you think, is it encrypted with sha1 or what?

Most likely SHA1, but it could be:

Code: Select all

sha1($value);
sha1(md5($value));
sha1( hash('whirlpool', $value) );
hash_hmac('sha1', $value, $key);


ETC

[samethings]

Hashes are made to be irreversible.

What do you mean by that?
If that`s the case then in what circumstances would someone encrypt it this way?

[shaqywacky]

What do you mean by that?
If that`s the case then in what circumstances would someone encrypt it this way?

To be clear, hashing and encryption are not the same. You do not 'encrypt' something with SHA1. You hash it. Encryption is reversible, hashing is not.

I think an example is the best way to explain the differences.

Say you want to encrypt the word 'cat'. A very simple way to do this would be to shift each letter backward by one place(IE a caesar cipher). So the 'c' would become a 'b', the 'a', would become a 'z' and the 't' would be come a 's'. So the encrypted word would be 'bzt'. If you want to get the original text back, you just shift everything forward by one letter. The 'b' becomes a 'c', ect. And you get 'cat' back.

Now say you want to hash 'cat'. A very simple(although not technically accurate, but it gets the point across) hash would be if you added the numerical(not ascii) value of each letter in the word together. So 'c' would be 3, 'a' would be 1, and 't' would be 20. You then add these( 3 + 1 + 20 ) and get 24. Now you want to get the original value back but there's a problem here. Many (infinite with real hashes) words will have the hashed value 24. For example, 'aaaaaaaaaaaaaaaaaaaaaaaa' would also have the value 24. So would 'ub'. So you can see that there is no way to get the original value back.

When someone 'cracks' a hash, they have just computed every permutation of characters until they found a hash that was the same as the hash they had. They can't say that the answer they found is the same, they just know they have the same hashed value.

[samethings]

What do you mean by that?
If that`s the case then in what circumstances would someone encrypt it this way?

To be clear, hashing and encryption are not the same. You do not 'encrypt' something with SHA1. You hash it. Encryption is reversible, hashing is not.

I think an example is the best way to explain the differences.

Say you want to encrypt the word 'cat'. A very simple way to do this would be to shift each letter backward by one place(IE a caesar cipher). So the 'c' would become a 'b', the 'a', would become a 'z' and the 't' would be come a 's'. So the encrypted word would be 'bzt'. If you want to get the original text back, you just shift everything forward by one letter. The 'b' becomes a 'c', ect. And you get 'cat' back.

Now say you want to hash 'cat'. A very simple(although not technically accurate, but it gets the point across) hash would be if you added the numerical(not ascii) value of each letter in the word together. So 'c' would be 3, 'a' would be 1, and 't' would be 20. You then add these( 3 + 1 + 20 ) and get 24. Now you want to get the original value back but there's a problem here. Many (infinite with real hashes) words will have the hashed value 24. For example, 'aaaaaaaaaaaaaaaaaaaaaaaa' would also have the value 24. So would 'ub'. So you can see that there is no way to get the original value back.

When someone 'cracks' a hash, they have just computed every permutation of characters until they found a hash that was the same as the hash they had. They can't say that the answer they found is the same, they just know they have the same hashed value.

Thanks a lot now I do get it but why would someone do that? What is the purpose of this process ? is it used for purposes of verifications... for example, in order to prevent hackers from stealing a pin number of a bank card, they will hash this code into a sum like the example you mentioned above. Then they use have another database with the first and the last digit of the bank account, so if a hacker does manage to get those first and last digit and knows that hash, it will not be easy to figure out the pin.

Or do you know any other example that might give me to understand where this hash is used for.

[LoGiCaL__]

Or do you know any other example that might give me to understand where this hash is used for.

Lets say you created and were in charge of a database and one of the tables included user info. Within this table was a field called passwords. You wouldn't and shouldn't store the user passwords in plain text. If it were to get hacked the hacker would have everyone's password who was registered within the database. So before storing it in the table you would hash it and then store the hashed value instead of the actual password. When a user logs in it takes the password entered hashes it, and then compares the hashed value to that stored within the database to verify the the correct user. If your going to google this, I would also check out "salting hashes" to getter a better understanding of this concept.