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DocumentationSecurity

Smart Contract Security

Smart contracts on Cardano are immutable once deployed. Understanding security principles and common vulnerabilities is essential for writing secure validators.

Security First: Always audit your contracts, test thoroughly, and consider professional security reviews before deploying to mainnet with significant value.

Authorization

  • Always verify signatures for state-changing operations
  • Use tx.signatories.contains(expectedSigner) checks
  • Implement multi-sig where appropriate

Input Validation

  • Validate all datum and redeemer inputs
  • Check value composition and amounts
  • Verify data structure sizes are bounded

Fail Secure

  • Design validators to reject by default
  • Use explicit require() checks for all conditions
  • Provide clear error messages

Comprehensive Testing

  • Test success paths
  • Test all failure cases
  • Test boundary conditions
  • Test with unauthorized actors
  • Use property-based testing

Audit and Review

  • Peer review all validator code
  • Professional audits for high-value contracts
  • Run bug bounties on testnet
  • Consider formal verification for critical logic

Summary

Writing secure Plutus validators requires careful attention to:

  1. Value validation - Control what tokens and amounts your script accepts
  2. Authorization - Always verify signatures and permissions
  3. Concurrency - Design for EUTxO model constraints
  4. Oracle security - Use TWAP, multiple sources, and freshness checks
  5. Mint validation - Explicitly check minting amounts and conditions
  6. Transaction validation - Verify all transaction components
  7. Testing - Comprehensive test coverage including attack scenarios

Security is not optional in smart contract development. Study common vulnerabilities, apply mitigations, and test exhaustively before mainnet deployment.

Resources

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Validity RangeCommon Vulnerabilities