Hi!
Is there any wallet software which guarantees that private keys are always committed to disk (using appropriate kernel primitives - there must be no chance that the key is still waiting in a write-behind cache) before being used on the network?
Thanks!
This answer is sort of cheating, but any deterministic wallet (Armory, Electrum, MultiBit HD) should qualify (even if it's not because they do so explicitly), assuming you do a reboot or a sync after initial wallet creation.
I wouldn't regard the usage of a deterministic wallet as "cheating", but of course a deterministic wallet comes with pros and cons of its own. But assuming that a reboot or sync is done by the user could be considered as "cheating". Basically, this would be the same as using a "regular" wallet software, and doing the private sync manually. I'm looking for something foolproof, where other components in the software stack can rely on every private key in use being persistently stored. If there is a deterministic wallet which enforces the sync in software, this would qualify (assuming that a deterministic wallet is applicable).