A blockchain-based smart contract operates independently once all the specified conditions are met, eliminating the need for intermediaries. The contract’s terms are written in code that can be read and executed by machines. Once the smart contract is complete, it becomes legally binding and irreversible. This raises the question of whether it is possible to terminate or reverse a smart contract.
This article explores the possibility of revoking smart contracts and provides insights into how one can revoke a smart contract’s access to their cryptocurrency holdings.
Revoking a smart contract typically involves disabling or terminating its functionality on the blockchain. For example, revoking a smart contract can prevent a user from accessing their crypto wallet or moving tokens. It can also halt permission to view a user’s token balance or public address.
There are several reasons why one may choose to revoke a smart contract. It could be because they no longer intend to buy, sell, or transfer an asset or use the smart contract again. In some cases, malicious developers may have built backdoors into smart contracts, allowing unauthorized access to funds.
Once the parties involved in a smart contract have agreed on the terms, the contract becomes unchangeable. The terms are written on the blockchain, which is immutable. However, it is possible to “upgrade” a contract by swapping it with another decentralized application’s underlying smart contract. Alternatively, parties can choose to have an upgradeable contract from the beginning, allowing for modifications.
No one controls a smart contract once its code is written into the blockchain. The code will execute when predetermined conditions are met or verified. Only the parties with access to the smart contract can see the transaction details. Therefore, it is crucial for the parties to clearly define the stipulations to ensure proper execution.
Tokens can be locked inside a smart contract, preventing them from being traded or withdrawn. The smart contract will only release the tokens after a specific period or certain conditions are met. Some platforms even allow users to customize the lockup period, specifying when the tokens can become available.
Token approvals and permissions play a significant role in smart contracts. They allow decentralized applications to automate the movement of tokens in a user’s wallet. Token approvals and permissions signify the owner’s approval for a smart contract to withdraw tokens from their wallet for trading purposes. To protect against potential exploitation, users can revoke smart contract access to their tokens.
Users can revoke smart contracts through token block explorers like Polygonscan and Etherscan. These explorers have approval sections where users can utilize the token approval tool to revoke permissions and approvals. The process involves navigating to the token approval page, searching for the address, connecting to the wallet, and selecting the contracts to revoke.
On the Ethereum mainnet, users can track and revoke smart contracts connected to their addresses using third-party tools like approved.zone, Revoke, EverRise, Ethallowance, Unrekt, Beefy.finance, Etherscan, and Cointool. By connecting their wallets to these tools, users can select the smart contracts they wish to revoke and complete the transaction.
Revoking token access to a smart contract does not terminate decentralized finance (DeFi) strategies. Users will retain their positions in DeFi strategies such as pooling, staking, and lending, allowing them to continue receiving rewards. However, revoking access can disrupt ongoing strategies that rely on the contract’s ability to interact with the tokens. The strategy will be paused or made inactive until access is granted again or adjustments are made.
Disconnecting a wallet from a project is different from removing permission to use funds. Disconnecting a wallet cancels permissions that allow others to view token balances, public addresses, and past activities, and it stops the initiation of transactions. However, it does not prevent the execution of transactions. Removing permission to use funds, on the other hand, revokes a DApp’s access to and movement of a wallet’s contents.