@Override
  public boolean isIdSigned(String id) {
    int searchStart = id.startsWith("/") ? 1 : 0;
    return id.startsWith(RestUtils.SIGNED_ID_PREFIX, searchStart);
  }
Reference implementation for an {@link IdSigningService}.
<p>
<b>Warning:</b> This implementation is not secure or tamper-proof, since it does not actually sign the data that it
is passed. A secure implementation would either need to use an authenticated encryption scheme or attach a signature.
ambry-frontend/src/main/java/com/github/ambry/frontend/AmbryIdSigningService.java