This is not even a secrets manager problem. Those have their place but it’s a different link in the chain, or I guess layer in the onion. The answer to this ty

This is not even a secrets manager problem. Those have their place but it’s a different link in the chain, or I guess layer in the onion. The answer to this type of thing is full disk encryption (FDE). There’s zero reason not to have it on every device at the block level. Especially if you’re going to be processing highly sensitive data. You can’t even trust disks to actually delete things anyway. So the only way to be sure that information is not leaked is to prevent it from ever being persisted to disk in plaintext.