Atlas One Smart Contracts is a suite of smart contracts adopted by Atlas One to support the creation and issuance of a controlled and permissed asset i.e. Digital Security Offering (DSO). The token contracts are compatible with the ERC20 and FA1.2 standards. The suite of contracts allow minting/burning tokens, pausing transfer activities, and ability to extend/share transfer restrictions.
Using OpenZeppelin's Access Control logic and design, the folowing roles are implemented for both Tezos and Ethereum. There can be multiple accounts per role using the Access Control.
See Tezos access control design doc here.
| Role | Description |
|---|---|
| Administrators | This role can act as the burner, minter and controller. It is also the only role that can grant and revoke roles. |
| Controllers | This role can operate on all tokens without permission as an intervention e.g. recover tokens from another wallet. |
| Minters | This role is granted to accounts or contracts that can mint tokens. |
| Burners | This role can be granted to any account of contract that can burn tokens. |
| Validators | The validator role is granted to another contract only that has restrictions set to validate a transaction. The current restriction is a shared Whitelist and Blacklist. |
| Partitioner | This role is granted to accounts or contracts that can change token partitions (currently used in ethereum ERC1400). |
| Operators | Token holders are operators of their own token. A token holder can grant another account the operator role to their tokens. |
| Role | Description |
|---|---|
| Pauser | This role can pause transactions. Only controllers can perform transactions when a contract is paused. |
The deployer is initially granted the administrator role in the Ethereum Contract but with Tezos, the storage can be initiatiated with multiple roles preconfigured. The administrator is the only role that can grant/revoke roles using the grantRole and revokeRole entrypoints. At role member has the ability to renounce their role using the renounceRole entrypoint.
NOTE: Atlas One maintains an administrative role to manage a token for an issuer.
The this validator checks the whitelist contract that maintains whitelist respective to each token:
| Role | Description |
|---|---|
| Administrators | This role can act as both the allow and block list roles. This is the only role that can grant/revoke roles. |
| Whitelist Administrator | This role can modify the whitelist list. |
| Blacklist Administrator | This role can modify the blacklist list. |
Granting, revoking and renoucing roles is similar to the explanation above.
NOTE: A controller/administrator can force transfer out of a blacklisted addresses
Contract transfers can be paused except for the controller in order to perform any intervention actions.
Minters can mint tokens as long as the contract can still issue tokens. Issuance can be renounced by the admin using the entrypoint renounceIssuance.
Burners can burn tokens at any time.
The current redemption stratergy is for a burner to burn the tokens after an off chain agreement.
The current stratergy is to make use of the controller role to perform a transfer on behalf of the token holder when they make an off chain transfer request. The TZIP-017 and EIP712 were not adopted in this suite but could be adopted to support feeless transactions without using the controller role.
Refrence Implementations:
- EIP712 MetaTransaction https://github.com/bcnmy/metatx-standard/blob/master/src/contracts/EIP712MetaTransaction.sol
- Gas Station Network (GSN) https://docs.openzeppelin.com/learn/sending-gasless-transactions
- Smartpy Permits/TZIP-017 https://github.com/EGuenz/smartpy-permits
- Ligo StableCoin Permits https://github.com/tqtezos/stablecoin
- Smartpy StableCoin with Feeless Transactions https://gitlab.com/tezos-paris-hub/eurotz-euro-stable-coin
TBD
TBD