How to find out the method used to encrypt [closed]

How to find out the method used to encrypt the string 123456 which results in the value: 6g9SkDLIKa8l2VhafFnHvg==?

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closed as off-topic by DrLecter, poncho, otus, e-sushi♦, Ilmari KaronenJun 29 '14 at 21:52

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "Requests for analyzing or deciphering a block of data are off-topic here, as the results are rarely useful to anyone else." – DrLecter, poncho, otus, e-sushi, Ilmari Karonen
If this question can be reworded to fit the rules in the help center, please edit the question.

1 Answer

You need to know Key, IV, Padding and Operation Mode. Then you have to try all possible algorithms. Without that (most likely very secret) information (Key, IV, Padding and Operation Mode) this is even more complex and hard to achieve than a know-plaintext attack. To sum it up: its impossible.

EDIT: As said, you can close the possibilities in. But you will not get any farther than a rugh idea of what cipher it is: Is it possible to derive the encryption method from encrypted text?

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