At 10:50 AM 4/26/96 -0500, Rick Smith wrote:

Having penned the response to Jeffrey Flinn on the unlikelihood of processor back doors, I'll comment on jim bell's response:

...

More likely,I think, an organization like the NSA might build a pin-compatible version of an existing, commonly-used product like a keyboard encoder chip that is designed to transmit (by RFI signals) the contents of what is typed at the keyboard. It's simple, it's hard to detect, and it gets what they want.

Simple, no.

By NSA standards, it is simple. NSA has probably had its own semiconductor fabs for 30+ years. Even if we assume that their capabilities lag commercial production in terms of density or quality, keyboard encoder chips were trivial 20+ years ago and could presumably be easily duplicated/modified today by even the oldest operating fabs. They probably had far less than 10,000 transistors. Even modern keyboard controllers probably "waste" a microcontroller with far more capability than you'd need for the task, and microcontrollers usually have substantially more code area than would be necessary to add some sort of surreptitious function.

Hard to detect, somewhat.

You'd have to know what to look for.

Gets what they want, unclear.

If there was one single data stream you'd like to get, it's the keyboard. This doesn't get you everything, but close.