Recovery Pallet

• recovery::Config
• Call

Overview

The Recovery pallet is an M-of-N social recovery tool for users to gain access to their accounts if the private key or other authentication mechanism is lost. Through this pallet, a user is able to make calls on-behalf-of another account which they have recovered. The recovery process is protected by trusted "friends" whom the original account owner chooses. A threshold (M) out of N friends are needed to give another account access to the recoverable account.

Recovery Configuration

The recovery process for each recoverable account can be configured by the account owner. They are able to choose:

• friends - The list of friends that the account owner trusts to protect the recovery process for their account.
• threshold - The number of friends that need to approve a recovery process for the account to be successfully recovered.
• delay_period - The minimum number of blocks after the beginning of the recovery process that need to pass before the account can be successfully recovered.

There is a configurable deposit that all users need to pay to create a recovery configuration. This deposit is composed of a base deposit plus a multiplier for the number of friends chosen. This deposit is returned in full when the account owner removes their recovery configuration.

Recovery Life Cycle

The intended life cycle of a successful recovery takes the following steps:

1. The account owner calls create_recovery to set up a recovery configuration for their account.
2. At some later time, the account owner loses access to their account and wants to recover it. Likely, they will need to create a new account and fund it with enough balance to support the transaction fees and the deposit for the recovery process.
3. Using this new account, they call initiate_recovery.
4. Then the account owner would contact their configured friends to vouch for the recovery attempt. The account owner would provide their old account id and the new account id, and friends would call vouch_recovery with those parameters.
5. Once a threshold number of friends have vouched for the recovery attempt, the account owner needs to wait until the delay period has passed, starting when they initiated the recovery process.
6. Now the account owner is able to call claim_recovery, which subsequently allows them to call as_recovered and directly make calls on-behalf-of the lost account.
7. Using the now recovered account, the account owner can call close_recovery on the recovery process they opened, reclaiming the recovery deposit they placed.
8. Then the account owner should then call remove_recovery to remove the recovery configuration on the recovered account and reclaim the recovery configuration deposit they placed.
9. Using as_recovered, the account owner is able to call any other pallets to clean up their state and reclaim any reserved or locked funds. They can then transfer all funds from the recovered account to the new account.
10. When the recovered account becomes reaped (i.e. its free and reserved balance drops to zero), the final recovery link is removed.

Malicious Recovery Attempts

Initializing a the recovery process for a recoverable account is open and permissionless. However, the recovery deposit is an economic deterrent that should disincentivize would-be attackers from trying to maliciously recover accounts.

The recovery deposit can always be claimed by the account which is trying to to be recovered. In the case of a malicious recovery attempt, the account owner who still has access to their account can claim the deposit and essentially punish the malicious user.

Furthermore, the malicious recovery attempt can only be successful if the attacker is also able to get enough friends to vouch for the recovery attempt. In the case where the account owner prevents a malicious recovery process, this pallet makes it near-zero cost to re-configure the recovery settings and remove/replace friends who are acting inappropriately.

Safety Considerations

It is important to note that this is a powerful pallet that can compromise the security of an account if used incorrectly. Some recommended practices for users of this pallet are:

• Configure a significant delay_period for your recovery process: As long as you have access to your recoverable account, you need only check the blockchain once every delay_period blocks to ensure that no recovery attempt is successful against your account. Using off-chain notification systems can help with this, but ultimately, setting a large delay_period means that even the most skilled attacker will need to wait this long before they can access your account.
• Use a high threshold of approvals: Setting a value of 1 for the threshold means that any of your friends would be able to recover your account. They would simply need to start a recovery process and approve their own process. Similarly, a threshold of 2 would mean that any 2 friends could work together to gain access to your account. The only way to prevent against these kinds of attacks is to choose a high threshold of approvals and select from a diverse friend group that would not be able to reasonably coordinate with one another.
• Reset your configuration over time: Since the entire deposit of creating a recovery configuration is returned to the user, the only cost of updating your recovery configuration is the transaction fees for the calls. Thus, it is strongly encouraged to regularly update your recovery configuration as your life changes and your relationship with new and existing friends change as well.

Interface

Dispatchable Functions

For General Users

• create_recovery - Create a recovery configuration for your account and make it recoverable.
• initiate_recovery - Start the recovery process for a recoverable account.

For Friends of a Recoverable Account

• vouch_recovery - As a friend of a recoverable account, vouch for a recovery attempt on the account.

For a User Who Successfully Recovered an Account

• claim_recovery - Claim access to the account that you have successfully completed the recovery process for.
• as_recovered - Send a transaction as an account that you have recovered. See other functions below.

For the Recoverable Account

• close_recovery - Close an active recovery process for your account and reclaim the recovery deposit.
• remove_recovery - Remove the recovery configuration from the account, making it un-recoverable.

For Super Users

• set_recovered - The ROOT origin is able to skip the recovery process and directly allow one account to access another.

License: Apache-2.0

Release

Polkadot SDK stable2409