Proxy accounts

Overview

Pallet Proxy enables accounts to grant specific permissions to other accounts, empowering them to make calls on their behalf, thereby safeguarding the security of the underlying accounts. On this page, you will find a detailed overview of the various proxy types, extrinsics, general definitions, and features associated with the proxy pallet. Additionally, there are tutorials available to help you understand and utilize the proxy functionality effectively.

Proxy Types

1. Any - This proxy type allows delegate account to make any call that is supported by proxy pallet. This is the highest level of privilege so should always use that with caution.

2. NonTransfer - This proxy type allows delegate account to make any call supported by proxy pallet expect for the asset transfer functionalities. This can come handy when you want to keep your funds secure in cold storage and want to delegate all the other functionalities to a proxy account. To see complete list of functionality, checkout the source code in Astar repo.

3. Balances - This proxy type gives control of handling accounts and balances to the delegate account. Complete list of calls can be found here.

4. Assets - This proxy type allows delegate account to control the functionalities related to fungible assets which includes asset issuance, transferal, minting etc. This is to be noted that this proxy types doesn't control the native currency like Astar or Shiden which are controlled by Balances proxy.

5. IdentityJudgement - This proxy type allows a single functionality to delegate account which is to provide a judgement to an identity in a naming system. The delegator must be a registrar.

6. CancelProxy - This proxy type allows delegate account to to reject and remove any announced proxy calls.

7. DappsStaking - This proxy type allows delegate account to perform DappStaking related transactions such as register, unregister contracts, claim rewards etc.

Extrinsics

The proxy pallet provides the following extrinsics (functions):

• addProxy(delegate, proxyType, delay) - allows the sender to register a proxy account capable of making calls on behalf of the sender. If the delay value is set to a number greater than 0, the proxy account must announce a transaction and wait for the specified number of blocks before executing it as a proxy. This function also emits a ProxyAdded event.

• announce(real, callHash) - used to record the announcement of a proxy transaction made by proxy accounts that have a delay requirement. This function emits an Announced event.

• anonymous(proxyType, delay, index) - generates a new account with an inaccessible private key, making it inaccessible. The sender assumes the role of a proxy for this account, based on the specified type and delay. Caution: If the proxy is removed, the primary account will become inaccessible. This function emits an AnonymousCreated event.

• killAnonymous(spawner, proxyType, index, height, extIndex) - removes a previously spawned anonymous proxy.

• proxy(real, forceProxyType, call) - performs a transaction as a proxy. This function emits a ProxyExecuted event.

• proxyAnnounced(delegate, real, forceProxyType, call) - executes a transaction as a proxy and removes any previous corresponding announcements. This function emits a ProxyExecuted event.

• rejectAnnouncement(delegate, callHash) - if the sender is a prime account, it removes a specific announcement from their proxy account.

• removeAnnouncement(real, callHash) - if the sender is a proxy account, it removes a specific announcement to their prime account.

• removeProxies() - unregisters all proxy accounts associated with the sender.

• removeProxy(delegate, proxyType, delay) - unregisters a specific proxy account linked to the sender. This function emits a ProxyRemoved event.

Constants for Pallet Proxy

Constant	Description
announcementDepositBase	base amount of currency required to reserve when creating an announcement.
announcementDepositFactor	amount of currency required per announcement made.
maxPending	maximum number of time-delayed announcements allowed to be pending.
maxProxies	maximum number of proxies permitted for a single account.
proxyDepositBase	base amount of currency required to reserve when creating a proxy.
proxyDepositFactor	amount of currency required per proxy added.

Why Proxy Deposits ?

To create proxies within the network, it is necessary to provide deposits in the native currency (like ASTR or SDN). The deposit is required because adding a proxy requires some storage space on-chain, which must be replicated across every peer in the network. Due to the costly nature of this, these functions could open up the network to a Denial-of-Service attack.

When creating a proxy, a bond is deducted from your free balance and transferred to your reserved balance. This mechanism helps maintain the integrity and stability of the proxy system while providing assurance that the bond can be returned when the proxy is deactivated or removed.

The required deposit amount for n proxies is equal to:

ProxyDepositBase + ProxyDepositFactor * n

Pure / Anonymous Proxy

Anonymous proxies (Pure Proxies) are freshly generated accounts, distinct from original one, which originate from a primary account. The primary account assumes the role of a proxy, representing the anonymous proxy. These proxies are non-deterministic and lack a private key, yet possess a randomly generated address. It is worth noting that anonymous proxies remain ownerless, as no individual possesses a private key to exercise control over them.

Despite their complexity and associated dangers, pure proxies have many important benefits like enhanced security and multi-sig account management.

tip

It is highly encouraged to checkout this documentation by Polkadot for more information about Pure proxy, its limitations and benefits.

Video resource for Pure Proxy - https://youtu.be/MqY6yU-YLO0

Time-Delayed Proxy

To enhance the security of proxies, we can implement a delay mechanism measured in blocks. A delay value of 10 corresponds to ten blocks, resulting in a delay of around two minute (for Astar network). The proxy will utilize the proxy.announce extrinsic to declare its intended action and will wait for the specified number of blocks according to the defined delay time before executing it.

During this delay window, the intended action can be canceled by either the proxy itself using the proxy.removeAnnouncement extrinsic or by the accounts controlling the proxy through the proxy.rejectAnnouncement extrinsic. The announcement made by the proxy includes the hash of the intended function call, enabling the identification and validation of the action.

By incorporating this delay mechanism, any malicious activities can be detected and reversed within the designated delay period. After the time-delay has passed, the proxy can proceed with executing the announced call using the proxy.proxyAnnounced extrinsic.

caution

Any attempt to sign the transaction using proxy extrinsic with pure proxy will fail. Read more about pure proxies here.

This implementation adds an additional layer of security to proxies, providing confidence in their usage, knowing that actions can be observed and undone within the specified delay period.

tip

Check out this video by Polkadot to learn how to set up time-delayed proxies.