The unsuitability of presigned transactions for vaults

[harding]

I wanted to add this point from @ajtowns in the other thread, which is an argument I do find compelling about the advantage of OP_VAULT over presigned transaction vaults.

@ajtowns

I don’t think pre-signed vaults really get the right security properties? As described in 2019:

One of the biggest problems with the vault scheme […] is an attacker that silently steals the hot wallet private key and waits for the vault’s owner to make a delayed-spend transaction to initiate a withdrawal from the vault. If the user was unaware of the theft of the key, then the attacker could steal the funds after the delay period.