Transport-level encryption with Tcpcrypt

The fact of the NSA disrupting the public introduction and even _discussion_ of cryptographic techniques isn't really up for debate. It's stated fairly plainly in their own documents: http://cryptome.org/0001/nsa-meyer.htm

From the horses (formerly top secret) mouth: "NSA hunted diligently for a way to stop cryptography from going public."

Though I've never seen any disclosure specific to the arpanet, it would be a logical consequence of the chilling effect of their academic suppression in other areas even absent direct intervention.

But really... would you have done differently in their shoes?