Here you can find the source of makeKey()
static Key makeKey()
//package com.java2s; import java.io.UnsupportedEncodingException; import java.security.Key; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import javax.crypto.spec.SecretKeySpec; public class Main { private static final String ENCRYPTION_KEY = "RwcmlVpg"; static Key makeKey() { return makeKey(ENCRYPTION_KEY); }/*from w w w.ja va2 s .c o m*/ static Key makeKey(String passkey) { try { MessageDigest md = MessageDigest.getInstance("SHA-256"); byte[] key = md.digest(passkey.getBytes("UTF-8")); return new SecretKeySpec(key, "AES"); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return null; } }