for initiate SDK requst, Hash sequence will be: <client_code>|<request_id>|<api_key>|<salt>
hash = SHA256(Hash-Sequence).
private String calculateHash(String clientCode, String requestId, String apiKey, String salt) throws NoSuchAlgorithmException { MessageDigest digest; digest = MessageDigest.getInstance("SHA-256"); if (digest != null) { byte[] hash = digest .digest( (clientCode + "|" + requestId + "|" + apiKey + "|" + salt) .getBytes() ); return bytesToHex(hash); } return null; } private final static char[] hexArray = "0123456789ABCDEF".toCharArray(); public static String bytesToHex(byte[] bytes) { char[] hexChars = new char[bytes.length * 2]; for (int j = 0; j < bytes.length; j++) { int v = bytes[j] & 0xFF; hexChars[j * 2] = hexArray[v >>> 4]; hexChars[j * 2 + 1] = hexArray[v & 0x0F]; } return new String(hexChars); }