To avoid problems on Windows with Anti-Virus software, there needs to be an option to obfuscate the keys/values written to the database files, especially the UTXO database.
See #4069 for discussion.

It should be really simple, just enough to make it useless to put AV signatures in transactions. E.g. generate a random key on first start, store the key in the database, then XOR all subsequent data read/written to the database with that.

Possibly this obfuscation could include the block files as well, although I've never heard of problems with those - the most likely explanation is that AV software doesn't consider files above a certain size.