The Digital Card Identification Smart Contract is a blockchain-based solution designed to issue, verify, and manage digital identification cards securely and efficiently. This smart contract leverages Ethereum blockchain technology to provide a decentralized, tamper-proof system for identity management, where users can own and manage their digital identity independently.
In today's digital age, identity management remains a significant challenge. Traditional systems rely on centralized authorities to issue, verify, and manage identification, which poses several issues:
- Security Risks: Centralized systems are vulnerable to hacking, data breaches, and unauthorized access, potentially compromising sensitive user data.
- Privacy Concerns: Users often have to trust third parties with their personal information, which can be misused or exposed.
- Inefficiency: Centralized systems may involve lengthy processes for identity verification, making them cumbersome for users and service providers.
The Digital Card Identification Smart Contract offers a decentralized alternative that addresses these problems by:
- Providing a Secure Identity Verification Mechanism: The smart contract uses cryptographic hashing to store and verify user identity data, ensuring that it remains secure and tamper-proof.
- Ensuring User Privacy: Only the hashed version of user data is stored on the blockchain, protecting personal information from exposure.
- Offering Decentralized Management: Users can manage their own digital identity without relying on a centralized authority, making the system more resilient and trustworthy.
- Each digital card is linked to a unique identifier, ensuring distinct and verifiable identities for all users.
- Admin Role: Administrators can issue, revoke, and manage digital cards.
- User Role: Regular users can claim, view, and share their digital cards.
- The contract stores only a cryptographic hash of the user's personal data, ensuring that sensitive information remains private.
- Digital cards can have an expiration date, and administrators can revoke them when necessary.
- Third parties can verify the authenticity of a digital card by comparing the provided data hash with the one stored on the blockchain.
- Optimized to reduce gas fees, with a focus on minimizing storage costs and unnecessary state changes.
- Reentrancy Guard: Prevents reentrancy attacks.
- Role-Based Access Control: Ensures only authorized users can perform critical operations like issuing and revoking cards.
User
Struct: Stores user-specific data includinguserAddress
,dataHash
,expirationDate
, andisValid
status.Mapping
: Maps each user's address to their correspondingUser
struct.
-
issueCard(address _userAddress, bytes32 _dataHash, uint256 _validityPeriodInSeconds)
:- Admin-only function to issue a new digital card.
- Takes the user's address, hashed data, and validity period as parameters.
- Stores the user data in the
users
mapping and emits aCardIssued
event.
-
revokeCard(address _userAddress)
:- Admin-only function to revoke an existing card.
- Sets the user's card
isValid
status tofalse
and emits aCardRevoked
event.
-
verifyCard(address _userAddress, bytes32 _providedDataHash)
:- Allows third parties to verify the validity of a digital card.
- Compares the provided data hash with the stored hash and checks the card's validity status and expiration date.
- Emits a
CardVerified
event and returns a boolean indicating whether the card is valid.
-
isCardValid(address _userAddress)
:- View function to check if a user's card is valid and not expired.
-
cleanupExpiredCard(address _userAddress)
:- Admin-only function to delete expired or revoked cards, freeing up storage and reducing gas costs.
-
withdraw()
:- Admin-only function to withdraw funds from the contract.
-
CardIssued(address indexed userAddress, uint256 expirationDate)
:- Emitted when a new digital card is issued.
-
CardRevoked(address indexed userAddress)
:- Emitted when a digital card is revoked.
-
CardVerified(address indexed verifier, address indexed userAddress, bool isValid)
:- Emitted when a digital card is verified by a third party.
- Reentrancy Protection: The contract uses the
ReentrancyGuard
from OpenZeppelin to prevent reentrancy attacks. - Data Privacy: User data is hashed before being stored on the blockchain, ensuring that personal information is not exposed.
- Role-Based Access Control: Only the contract owner can issue or revoke cards, ensuring that only authorized actions are performed.
- Efficient Use of Storage: The contract minimizes storage operations and allows for the deletion of expired or revoked cards to reduce gas costs.
- Mapping-Based Access: Using mappings for user data ensures efficient data retrieval and storage.
- Node.js and npm
- Hardhat: A development environment for Ethereum.
- Clone the Repository:
git clone https://github.com/KAMBALENGUNUNU/DigitalCardIdentification.git