javaInt4Bytes

Signature A valid digital signature gives a recipient reason to believe that the message was created by a known sender ( authentication ), that the sender cannot deny having sent the message ( non-repudiation ), and that the message was not altered in transit ( integrity )   Original-data.getByte() + private key à signature All are in byte array As signature has to be passed through network, we convert into string but we cant use just string of original byte array because of security. Hence we do manipulation of byte array and convert into a different string. We shoud not send new String(byte [] signature) , we should send   new String(Base64.encode(byte[] signature)) Verification: Client send (new data + signature) object{ User name: Ram Id : 678 Signature : ZTngSmnSpmWIj40r5TQ1hmec0UbfJLSCRSxbVBxCwchcFu6A8RS+O9BUFgG7U+UozVlrO5xGl9tARHxcIK4y2x/UHvhfYu74SOq22XgdGNuPMGQ560pUpiSkXspfGuFh9xHqovNGs7MQvWyESgurqehdsFD18sXV0z7gnqqFm78= }