Generating and Verifying a Signature Using Generated Keys

The following signature generation and verification examples use the key pair generated in the key pair example.

Generating a Signature
We first create a signature object:
Signature dsa = Signature.getInstance("SHA1withDSA");
Next, using the key pair generated in the key pair example, we initialize the object with the private key, and then sign a byte array called data.
/* Initializing the object with a private key */
PrivateKey priv = pair.getPrivate();

/* Update and sign the data */
byte[] sig = dsa.sign();
Verifying a Signature
Verifying the signature is straightforward. (Note that here we also use the key pair generated in the key pair example.)
/* Initializing the object with the public key */
PublicKey pub = pair.getPublic();

/* Update and verify the data */
boolean verifies = dsa.verify(sig);
System.out.println("signature verifies: " + verifies);