Sure, just lock it down cryptographically, not just with a password. Use a local database encrypted with a key you never store on the cloud. Generate a hash of every entry, chain them like a block chain so tampering shows a mismatch. Then write a tiny daemon that watches the file system; if the file is modified, it reverts to the last good hash or alerts you. For extra safety, keep a copy on a read‑only USB in a safe. That way only you can rewrite it, and any attempt to change it is immediately noticed.