Tectia Client doesn't provide a .NET API. Tectia ConnectSecure does provide an API for secure file transfer but it's only available in C and Java.
To answer your question I guess it depends on how the application has been developed to interact with Tectia Client.
Since no API is available, and indeed is using Tectia Client, my only guess is that the application executes the Tectia Client command line tools (sshg3/scpg3/sftpg3). So if this is the case then it depends on the .NET framework classes and functions used to call these and whether these have changed from 2.0 to 4.0.
answered Mar 09 '11 at 19:06