<p>Verifies a digital signature that was generated by the <a>Sign</a> operation. </p> <p/> <p>Verification confirms that an authorized user signed the message with the specified KMS key and signing algorithm, and the message hasn't changed since it was signed. If the signature is verified, the value of the <code>SignatureValid</code> field in the response is <code>True</code>. If the signature verification fails, the <code>Verify</code> operation fails with an <code>KMSInvalidSignatureException</code> exception.</p> <p>A digital signature is generated by using the private key in an asymmetric KMS key. The signature is verified by using the public key in the same asymmetric KMS key. For information about asymmetric KMS keys, see <a href="https://docs.aws.amazon.com/kms/latest/developerguide/symmetric-asymmetric.html">Asymmetric KMS keys</a> in the <i>Key Management Service Developer Guide</i>.</p> <p>To use the <code>Verify</code> operation, specify the same asymmetric KMS key, message, and signing algorithm that were used to produce the signature. The message type does not need to be the same as the one used for signing, but it must indicate whether the value of the <code>Message</code> parameter should be hashed as part of the verification process.</p> <p>You can also verify the digital signature by using the public key of the KMS key outside of KMS. Use the <a>GetPublicKey</a> operation to download the public key in the asymmetric KMS key and then use the public key to verify the signature outside of KMS. The advantage of using the <code>Verify</code> operation is that it is performed within KMS. As a result, it's easy to call, the operation is performed within the FIPS boundary, it is logged in CloudTrail, and you can use key policy and IAM policy to determine who is authorized to use the KMS key to verify signatures.</p> <p>To verify a signature outside of KMS with an SM2 public key (China Regions only), you must specify the distinguishing ID. By default, KMS uses <code>1234567812345678</code> as the distinguishing ID. For more information, see <a href="https://docs.aws.amazon.com/kms/latest/developerguide/asymmetric-key-specs.html#key-spec-sm-offline-verification">Offline verification with SM2 key pairs</a>.</p> <p>The KMS key that you use for this operation must be in a compatible key state. For details, see <a href="https://docs.aws.amazon.com/kms/latest/developerguide/key-state.html">Key states of KMS keys</a> in the <i>Key Management Service Developer Guide</i>.</p> <p> <b>Cross-account use</b>: Yes. To perform this operation with a KMS key in a different Amazon Web Services account, specify the key ARN or alias ARN in the value of the <code>KeyId</code> parameter. </p> <p> <b>Required permissions</b>: <a href="https://docs.aws.amazon.com/kms/latest/developerguide/kms-api-permissions-reference.html">kms:Verify</a> (key policy)</p> <p> <b>Related operations</b>: <a>Sign</a> </p>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}