Jim Choate wrote :
Forwarded message:
Date: Sun, 6 Jul 1997 06:43:06 -0400 (edt) From: Ryan Anderson <randerso@ece.eng.wayne.edu> Subject: Re: Hack the Mars rover
The place to attack is the up-link. This requires physical access (ie a van with a dish and xmtr.) as well as a means to crack the encryption on the control channels. At least one French satellite has been cracked and de-orbited via a network attack.
Besides, how much encryption is needed between two points if intercepting the traffic is expensive, the communications protocol is undocumented (as far as anyone outside NASA is concerned), and the actual frequency is also hard to find?
The communications are not only documented but easily observable with the correct commercialy available equipment. The frequencies are a matter of public record, I would further bet that 5 minutes with a search engine would bring that data to light...
Two very imprtant points. The space path loss to and from Mars is very large. So a very large dish is required to have sufficient G/T to see readable data. Most NASA deep space stations use 85 foot dishes and some also have 300 footers. Without that kind of antenna gain one is not going to see anything at all, and without that kind of gain on the command uplink as well as a multi KW high power microwave amplifier to feed the dish one is not going to be able to put enough signal into Mars to do anything. There are essentially no 85 foot or larger dishes in the hands of anyone who might be attempting to hack a NASA spacecraft. Such an antenna is simply not your back yard satellite dish.... they cost more than a million dollars and are major construction projects. The second point is that the NSA has been supplying space hardened crypto chips and related ground equipment to every US satellite manufacturer and operator for at least the last 15 years for use in protecting the command uplinks against unauthorized access. One can be quite sure that NASA has used these, or if they haven't has good reason to believe they don't have to. The attack that is barely conceivable is for some cracker to break into a NASA terrestrial communications link associated with the Deep Space Network (some links use satellite communications for example and others microwave links) and access the command uplink systems of a NASA DSN site. Whether they have fully secured all of these against such attack is unclear. Obviously good old secret key encryption would work here, and there certainly is a lot of command validation done at the uplink before the command is sent, so whoever was doing this would have to have great in-depth knowlage of the command uplink system and the spacecraft itself. And finally, demodulating the downlinks and recovering information from them is relatively easily accomplished once the hard part (obtaining the G/T required) is somehow handled. NASA tends to use very straightforward modulations and FEC and does not encrypt the downlinks. And a fair amount of detail about the data formats is publicly available. Dave Emery die@die.com Weston, Mass.