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In wiki about RC4 cipher they said,

Because the algorithm is known, it is no longer a trade secret.

Is that mean the cipher text will be more secure if the algorithm unknown to the attacker.

About AES is it really full paper public so anyone with knowledge can read how its work or there is something hidden

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closed as not a real question by fgrieu, Paŭlo Ebermann Oct 22 '12 at 17:36

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

The question is mostly rhetorical. Also it is not about "algorithm-design", much less "algebraic-attack" as tagged. The question asked formally seems to be: "does the quoted text mean that cipher text will be more secure if the algorithm is unknown to the attacker?", and the answer is obviously: no, the quoted text does not mean or imply that. The quoted text exposes a fact following from the legal definition of trade secret in US law, nothing more; it has nothing to do with cryptography. – fgrieu Oct 22 '12 at 11:18
The quote is about the legal status of trade secret, not about the security of some algorithm. In general, have a look at Kerkhoffs's principle. – Paŭlo Ebermann Oct 22 '12 at 17:40
up vote 3 down vote accepted

Question: Are ciphertexts produced by secret (unknown to the public) algorithms more secure than those produced by public algorithms like AES?

Answer: No. The reverse! Public algorithms (like AES) have been examined by professional cryptographers all over the world. In contrast, secret algorithms, by definition, have not been subject to that process at all — so why would you think those algorithms could possibly more secure than public ones?

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I don't think you can definitively say no, secret algorithms are not more secure. – mikeazo Oct 22 '12 at 11:36
But how come hide encryption system didnt improve security, if you dont know the system you have totally random letters it must increase security? as u need to know the system then find the key ??? i'm a little new in encryption just read about and hope to design my hand cipher – illsecure Oct 22 '12 at 16:15
@illsecure, there is a field of study called cryptanalysis that is about studying the "totally random letters" and unscrambling them. Enigma, the very complex electromechanical rotor system used by the Germans in WWII, was an unknown system yet was broken by the Allies. – John Deters Oct 22 '12 at 18:58
@John Deters: To be fair and accurate, Enigma was not broken because it was a weak algorithm, it was broken because it was not implimented correctly(human error). – William Hird Oct 22 '12 at 22:57
@JohnDeters: Enigma was NOT "an unknown system" for its cryptanalysts; they had access to the design. Sometime, when unknown rotors have been introduced, that blocked cryptanalysis. – fgrieu Oct 23 '12 at 5:25

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