rsa = Cipher.getInstance("RSA");
rsa.init(Cipher.ENCRYPT_MODE, keyPair2.getPrivate());
byte[] signatureNew = rsa.doFinal(hash);
// change data signature to keys 2, assign the reused hash from signature
data = new Data().ttlSeconds(ttl).signature(codec.decode(signatureNew)).setProtectedEntry();
// don't forget to set signed flag, create meta data
data.signed(true).duplicateMeta();
// put meta using content content protection key 1 to sign message
FuturePut futurePutMeta = p1.put(lKey).setDomainKey(dKey).putMeta().setData(cKey, data)
.setVersionKey(vKey).keyPair(keyPair1).start();