Methods and systems including: receiving a request to take an action in a cryptoasset custodial system for an account holder; authenticating a policy map associated with the action, wherein the policy map defines access control rules governing which actions are allowed under conditions including a threshold number of endorsements needed; and validating endorsement messages for the action by checking digital signatures of the received endorsement messages, wherein at least one of the validated endorsement messages has been generated by digital signing with a first private key of a person, who is associated with the account holder, and at least one of the validated endorsement messages has been generated by digital signing with a second private key of a program, which is associated with the account holder, responsive to the program confirming one or more circumstances specified by the account holder are met at a time when the program is run.