reuse in implementations is common, and most protocols need to handle an asynchronous "offline" mode which means a sliding window of valid counters, and a threa

reuse in implementations is common, and most protocols need to handle an asynchronous "offline" mode which means a sliding window of valid counters, and a thread to pull. the difference between a single use key and a limited use key is significant and has been known to get fudged somewhere between approved spec and implementation. Sure don't reuse the IV and make sure it can't be easily derived or guessed, but if I'm looking for problems in an implementation, my point was that counter usage is one of the low-entropy threads to pull.