Skip to main content
Research Preview — APIs may change. GitHub

​
Security considerations

This page documents the security model, known limitations, and best practices for building with Astral.

​
Astral signer address

Current Astral Signer (Base Sepolia): 0x590fdb53ed3f0B52694876d42367192a5336700FResolver contracts must verify that attestation.attester equals this address. See Staging for the full configuration.

​
Known considerations

​
Replay attacks

Status: Documented, resolver responsibility Signed results could potentially be reused:
  • Temporal replay: Old result used for current benefit
  • Cross-context replay: Result for one resolver used at another
Mitigations (your responsibility): 
contract SecureResolver is SchemaResolver {
    mapping(bytes32 => bool) public usedAttestations;

    function onAttest(Attestation calldata attestation, uint256)
        internal override returns (bool)
    {
        // 1. Check not already used
        bytes32 attHash = keccak256(abi.encode(attestation.uid));
        require(!usedAttestations[attHash], "Already used");
        usedAttestations[attHash] = true;

        // 2. Check timestamp freshness
        (, , uint64 timestamp, ) = abi.decode(...);
        require(timestamp > block.timestamp - 1 hours, "Too old");

        // 3. Verify expected inputs
        (, bytes32[] memory inputRefs, , ) = abi.decode(...);
        require(inputRefs[1] == EXPECTED_LOCATION, "Wrong location");

        // ... business logic
    }
}

​
Input trust

Status: Raw GeoJSON not verified Raw GeoJSON inputs are accepted for flexibility, but are not verified for authenticity: 
// This works but geometry source is unverified
const result = await astral.compute.contains(
  { type: 'Polygon', coordinates: [...] },  // Raw, unverified
  userLocationUID
);
The signed result proves:
  • “Astral computed the relationship between A and B”
It does not prove:
  • “Geometry A came from a trusted source”
  • “User was actually at location B”
Best practice: For high-security applications, require attested inputs (UIDs) rather than raw GeoJSON.

​
GPS spoofing

Status: Out of scope for MVP Astral can verify that a computation was correct, but cannot verify that the input location represents where the user actually was. GPS can be spoofed. Future: Location proofs with multiple corroborating stamps will make spoofing harder.

​
Best practices

​
For resolver authors

require(attestation.attester == astralSigner, "Not from Astral");

require(timestamp > block.timestamp - MAX_AGE, "Attestation too old");

require(inputRefs[1] == EXPECTED_LANDMARK, "Wrong location checked");

require(!usedAttestations[uid], "Already used");
usedAttestations[uid] = true;

function updateSigner(address newSigner) external onlyOwner {
    astralSigner = newSigner;
}

​
For application developers

  • Prefer UIDs over raw GeoJSON for sensitive operations
  • Set appropriate timeouts — don’t accept stale results
  • Validate recipient — ensure the result is for the right user
  • Handle signature expiry — delegated attestation signatures have deadlines

​
Key management

​
Service signing key

  • Key generated or provisioned within TEE
  • Cannot be extracted by operators
  • Used to sign all results

​
Key rotation

Resolver contracts should support key rotation: 
address public astralSigner;

event SignerUpdated(address oldSigner, address newSigner);

function updateAstralSigner(address newSigner) external onlyOwner {
    emit SignerUpdated(astralSigner, newSigner);
    astralSigner = newSigner;
}
For the research preview, a simple owner-controlled update is sufficient. For production, consider making the owner a multisig.

​
Audit status

ComponentStatus
Compute ServicePending
SDKPending
Example ContractsPending
Full security audit will be conducted before mainnet deployment.