We already know that the encryption behind BitCoin is sound. But every time encryption has been challenged in recent days it's been because of a bug in the impl

We already know that the encryption behind BitCoin is sound. But every time encryption has been challenged in recent days it's been because of a bug in the implementation of that encryption. It is never due to some ingenious brute force algorithm that actually breaks the key. The question we really need to be asking is - have all the major vulnerabilities in the implementation of BitCoin - the ones that could actually threaten its existence - been discovered? Are we sure? I say this as someone who has been evangelizing to everyone he knows about BitCoin.