I think the essence is that while both are encryption, one is applied
to transport and one to storage.  Thus, were we starting fresh I'd
recommend

  transport_encryption
  storage_encryption

Since we aren't, I think we should go with

  encryption            # transport, but holding disk and tapes are cleartext
  server_storage_encryption     # bits on tape are encrypted by server
  client_storage_encryption     # bits on tape are encrypted by client

This is wordy, and it blurs service and mechanism, but it will help
people to understand what they need.