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The following engine classes are available: SecureRandom : used to generate random or pseudo-random numbers.              SecureRandom secureRandom = new SecureRandom()              secureRandom.getInstance();              secureRandom.getInstanceStrong()              synchronized public void setSeed(byte[] seed)              public void setSeed(long seed)              synchronized public void nextBytes(byte[] bytes)              byte[] generateSeed(int numBytes) MessageDigest : used to calculate the message digest (hash) of specified data. Signature : initialized with keys, these are used to sign data and verify digital signatures. Cipher : initialized with keys, these used for encrypting/decrypting data. There are various types...

         Cryptography is the practice and study of hiding and secure information such as security, including language safety, cryptography, public key infrastructure, authentication, secure communication, and access control.

Destination Net Unreachable If your computer is connected a router or a shared network, and you are requesting for PING from your computer. Your computer fail to find the network destination / IP and your computer will get "Destination net Unreachable" error message. CMD --------------------------------------------------------------------------------------------------------------- Microsoft Windows [Version 6.1.7600] Copyright (c) 2017 Microsoft Corporation.  All rights reserved. C:\Users\xyz> ping 1.2.3.4 Pinging 1.2.3.4 with 32 bytes of data: Reply from 192.168.0.129: Destination net unreachable. Reply from 192.168.0.129: Destination net unreachable. Reply from 192.168.0.129: Destination net unreachable. Reply from 192.168.0.129: Destination net unreachable.