Trying to understand Java RSA key size
- by Tom Brito
The key generator was initilized with a size of 1024, so why the printed sizes are 635 and 162?
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
public class TEST {
public static KeyPair generateKeyPair() throws NoSuchAlgorithmException, NoSuchProviderException {
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA", "BC");
keyPairGenerator.initialize(1024);
return keyPairGenerator.generateKeyPair();
}
public static void main(String[] args) throws Exception {
KeyPair keyPair = generateKeyPair();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
System.out.println("Size = " + privateKey.getEncoded().length);
System.out.println("Size = " + publicKey.getEncoded().length);
}
}
