Quote from: user2015 on March 12, 2015, 07:21:32 PM

So the question is... Is it possible to get the seed back,by knowing the code above? Some help would be realy appreciated! Thanks!

No, not by the encrypted seed alone.

First, understand what AES encryption does. It takes input data and jumbles it up into random looking data... When you test a password, the only way you can know if it's the right password is if you get back the original message.

Why does this matter?

With Electrum 1.x, the "message" being encrypted is 16 random bytes of information (the decoded seed)... so the only way to know whether you got the password correct or not is to do the following:

1. Decrypt with AES and your password attempt.
2. Hash the result with itself 100000 times.
3. Use that final hash as a private key and find the x and y values of the public key.
4. Compare the x and y values to your wallet's MPK (master public key) and if they are equal, then your passphrase was correct.

So as I have shown in step 4, you ALSO need the MPK (it should be 128 character hexidecimal (0-9A-F) string) of the wallet that contained that encrypted seed.

1.x wallets store the MPK as

Code:

"mpk": "f3b9ecda...7ca3bef7"

If you would like to make a script that tests many passwords, you will first have to understand how to derive from the decoded seed to the master public key.