Secure Network File System performance considerations

There are several ways that secure NFS affects system performance.

• Both the client and server must compute the common key. The time it takes to compute the common key is about one second. As a result, it takes about two seconds to establish the initial RPC connection, because both client and server have to perform this operation. After the initial RPC connection, the key server caches the results of previous computations, and so it does not have to recompute the common key every time.
• Each RPC transaction requires the following DES encryption operations:
  1. The client encrypts the request time stamp.
  2. The server decrypts it.
  3. The server encrypts the reply time stamp.
  4. The client decrypts it.

Because system performance can be reduced by secure NFS, weigh the benefits of increased security against system-performance requirements.