Verify payload integrity and cryptographic identity before trusted execution.
Execute real-time cryptographic verification on transactional payloads. Tamper with the data to witness immediate hash divergence and signature rejection.
{
"transactionId": "NW-8F21A7",
"amount": 18450,
"currency": "USD",
"recipient": "nonceworks-secure",
"timestamp": "2026-09-21T14:32:18Z"
}CALCULATING...Deterministic cryptographic digest calculated in real time directly from the canonical payload string.
q3Kp7vL2b9XfQ2mY8rZ1tW4uE7oP0sA5dF8gH1jK3lM6nB9vC2xZ5aQ8wE1rT4yU7iO0pS3dF6gH9jK2lM5nB8vC1xZ4aQ7wE0rT3yU6iO9pS2dF5gH8jK1lM4nB7vC0xZ3aQ6wE9rT2yU5iO8pS1dF4gH7jK0lM3nB6vC9xZ2aQ5wE8rT1yU4iO7pS0dF3gH6jK9lM2nB5vC8xZ1aQ4wE7rT0yU3iO6pS9dF2gH5jK8lM1nB4vC7xZ0aQ3wE6rT9yU2iO5pS8dF1gH4jK7lM0nB3vC6xZ9aQ2wE5rT8yU1iO4pS7dF0gH3jK6==Fixed demonstration signature fixture corresponding to the original payload and public key.
While this frontend demonstration calculates digests in the browser, the intended production deployment delegates all verification decisions to an isolated Java / Spring Boot security engine.
The security API receives the transaction payload and signature verification envelope over an authenticated, TLS-encrypted endpoint.
The payload is normalized according to strict protocol standards and hashed using SHA-256 to ensure data immutability.
The Java/Spring Boot security engine uses Java Cryptography Architecture (JCA) and designated public keys to decrypt and verify the signature.
The engine makes an atomic, deterministic comparison between the decrypted hash and the computed payload digest.
The verification decision, cryptographic telemetry, and audit logs are returned to the operator console or caller system.
package com.nonceworks.security.engine;
import java.security.PublicKey;
import java.security.Signature;
import java.security.spec.MGF1ParameterSpec;
import java.security.spec.PSSParameterSpec;
import java.util.Base64;
import org.springframework.stereotype.Service;
@Service
public class CryptographicVerificationEngine {
/**
* Verifies an RSA-PSS digital signature using Java Cryptography Architecture (JCA).
*/
public boolean verifySignature(byte[] payloadBytes, String signatureBase64, PublicKey publicKey)
throws Exception {
Signature signature = Signature.getInstance("RSASSA-PSS");
PSSParameterSpec pssParams = new PSSParameterSpec(
"SHA-256", "MGF1", MGF1ParameterSpec.SHA256, 32, 1
);
signature.setParameter(pssParams);
signature.initVerify(publicKey);
signature.update(payloadBytes);
byte[] signatureBytes = Base64.getDecoder().decode(signatureBase64);
return signature.verify(signatureBytes);
}
}