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0 pointshiq6y ago0 comments

Is there a way to use ECB "correctly"?

Is there any non-repeating data apart from noise (if even)?

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Yes, as I mentioned, if you include an incrementing counter within each block then the data does not repeat. The data only needs to be non-repeating within a single stream. Different streams will use a different IV and possibly different keys. This is how CTR works.

katzenjam6y ago

Including a counter in each UDP packet does not make ECB mode equivalent to CTR mode.

Let's assume the counter is at the start of the packet. An AES block is 16 bytes, so the counter ensures the first 16 bytes of ciphertext are unique across packets. But any patterns in the remainder of the packet are preserved, within and across packets.

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Diggsey6y ago

katzenjam6y ago

Including a counter in each UDP packet does not make ECB mode equivalent to CTR mode.

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