@Override
  public OutputStream createEncryptionStream(OutputStream out, Context context, byte[] iv)
    throws IOException {
    Preconditions.checkNotNull(context);
    Preconditions.checkState(context.getKey() != null, "Context does not have a key");
    Preconditions.checkNotNull(iv);
    Encryptor e = getEncryptor();
    e.setKey(context.getKey());
    e.setIv(iv);
    return e.createEncryptionStream(out);
  }
AES-128, provided by the JCE
<p>
Algorithm instances are pooled for reuse, so the cipher provider and mode are configurable but
fixed at instantiation.
hbase-common/src/main/java/org/apache/hadoop/hbase/io/crypto/aes/AES.java