Since starting to use Kerberos [1]. which pro- vides the option to encrypt rlogin sessions at the application layer. we noticed that using encryp- tion caused a severe performance impact across dial-up lines. e.g.. a 14.4kbps line using PPP with modem compression of data. We took measurements and verified the source of the problem as a non-synergistic interaction be- tween the application. transport. and lower net- work layers. We modified the Kerberized rlogin (klogin) to accommodate this situation. and will make the modifications publicly available. Since normal ascii tert data is quite compressible. this modification could become important for ubiqui- tous low speed access.