You are right - see my note [0] but I missed the bleedin obvious. Thanks for pointing it out. In that case the hardware is effectively broken and all that's le

You are right - see my note [0] but I missed the bleedin obvious. Thanks for pointing it out. In that case the hardware is effectively broken and all that's left is attempted software mitigation. Which may/may not work, but surely will cost performance. And extra complexity. And consequential possible bugs. From memory a key can be represented as a random 64-bit integer taken from a sparse set. IOW you'd have bugger all chance of guessing another currently used 64-bit int, and if you tried and guessed wrong the OS, which would keep a list of caps allocated to each process) would say when you tried to use it "and where exactly did this come from, eh?" and kill you. But that's from memory and guesswork. HTH and don't trust what I say too much!