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CCM specifies (Section 1.7) that no plaintext data should be released before the MAC is verified.

Why is this recommendation given and what attacks are possible against CCM if data is treated like a streaming operation and decrypted data is released before the MAC is verified?

Is this recommendation given because of user temptation to use unverified data without checking the MAC? Or are there deeper ramifications?

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Is this recommendation given because of user temptation to use unverified data without checking the MAC?

Yes. Note the word "released" instead of "stored".

Or are there deeper ramifications?

That should not be possible; CCM uses CBC-MAC with known length and CTR mode encryption. There are - to my knowledge - no known plaintext attacks possible on these algorithms (given that the underlying block cipher is secure, of course).

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