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Security Best Practices

Guidelines for building secure applications on Specter.

Commitment secrets​

  • Never reuse secrets — each commitment must have unique secret, nullifierSecret, and blinding values
  • Use cryptographically random values — generate secrets from crypto.getRandomValues() or crypto.randomBytes(), never from predictable sources
  • Store securely — commitment secrets are the only way to reveal committed tokens. If lost, tokens are permanently unrecoverable
  • Never transmit in plaintext — if using the commitment relayer or proof relayer, understand that the operator can see your secrets. For maximum privacy, compute hashes and proofs client-side

Smart contract security​

  • Use ReentrancyGuard — all contracts interacting with the vault should be non-reentrant
  • Check return values — verify that precompile calls return true
  • Set gas limits — policy validation is capped at 100K gas, but your own contracts should use appropriate gas limits
  • Follow CEI pattern — checks-effects-interactions to prevent reentrancy

Gas price​

  • Always set explicitly — eth_gasPrice may return 0. Use 1 gwei minimum.
  • Don't rely on gas estimation — Cosmos EVM gas estimation may differ from Ethereum

Key management​

  • Separate testnet and mainnet keys — never use testnet keys for real funds
  • Use hardware wallets for production deployments
  • Rotate deployer keys after initial deployment

Privacy considerations​

  • Use fresh addresses for reveals — revealing to your commit address defeats the privacy purpose
  • Wait before revealing — immediate reveals narrow the anonymity set
  • Batch with other users — privacy improves with more commitments in the tree
  • Don't link on-chain behavior — avoid patterns that correlate your commit and reveal addresses

Policy security​

  • Verify policy logic — policies are called via staticcall and cannot modify state, but they can read any on-chain data
  • Test policy edge cases — expired timelocks, boundary conditions, zero values
  • Keep gas usage low — policies exceeding 100K gas will fail silently