docs: def freeze_encrypt(dest_dir, zip_filename, config, opt):
      """Encrypts the zip file"""
      pgp_keys = grok_keys(config)
      icefile_prefix = "aomi-%s" % \
                       os.path.basename(os.path.dirname(opt.secretfile))
      if opt.icefile_prefix:
          icefile_prefix = opt.icefile_prefix
  
      timestamp = time.strftime("%H%M%S-%m-%d-%Y",
                                datetime.datetime.now().timetuple())
      ice_file = "%s/%s-%s.ice" % (dest_dir, icefile_prefix, timestamp)
      if not encrypt(zip_filename, ice_file, pgp_keys):
          raise aomi.exceptions.GPG("Unable to encrypt zipfile")
  
      return ice_file