Java Programming

I am calling a SOAP Webservice to fetch the public key in the form of byte[] .

I want to encrypt some input text with this public key using RSA Encryption in java.

I am using the below class:

public class CryptographyUtil {
    private static final String ALGORITHM = "RSA";
    public static byte[] encrypt(byte[] publicKey, byte[] inputData)
            throws Exception {
        PublicKey key = KeyFactory.getInstance(ALGORITHM).generatePublic(new X509EncodedKeySpec(publicKey));
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.PUBLIC_KEY, key);
        byte[] encryptedBytes = cipher.doFinal(inputData);
        return encryptedBytes;
    }
}

I am calling the above:

String text = "1234";            
byte[] c = CryptographyUtil.encrypt(publickKey.getBytes(), text.getBytes() );

But i am getting  the below exception

java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: invalid key format

  at sun.security.rsa.RSAKeyFactory.engineGeneratePublic(RSAKeyFactory.java:188)

How can i resolve this?