I hope this is the right place to ask this:(adsbygoogle = window.adsbygoogle || []).push({});

So looking at a symmetric encryption scheme, we see that a simple, say, xor of the data with the secret key will be broken in the event of single known-plaintext attack. Obviously, then, it is intuitive to pad out all plaintext with a random value, and of course perform a simple reversable operation to obfuscate the content so portions of the key cannot be retrieved piecemeal in a known-plaintext attack. One could, for example, compress the plaintext in an encrypted archive using a random value for a key, and then append the random value to the archive and xor the whole thing with the secret key. I understand that this is not actually cryptographically secure. I just don't understand why. What form would attacks against such a method or a similar one take?

(level of math I can handle: out of practice, but first year university math I generally remember)

sincerely,

thatwouldbeme

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# Encryption question

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