System.arraycopy(label, 0, seed, 0, label.length);
System.arraycopy(nonce, 0, seed, label.length, nonce.length);
DerivationAlgorithm algo = AlgoFactory.getInstance(ConversationConstants.DerivationAlgorithm.P_SHA_1);
this.derivedKeyBytes = algo.createKey(this.ephemeralKey, seed, offset, length);
//Add the DKTs
dkt = new DerivedKeyToken(this.wscVersion, document);
dktId = "derivedKeyId-" + dkt.hashCode();