Calling NSA to find your encryption key after a few bits were flipped (2010)
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Calling NSA to find your encryption key after a few bits were flipped (2010)
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Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#2That's pretty fascinating. I admit I find it kind of strange that only the encryption key was affected in this way, i.e. that finding the newly-correct key proved a fix to the issues, as opposed to fixing one issue out of many linked to such an event.
It made me wonder--what are the odds of that? What is the relative exposure area of the encryption key compared to the rest of the onboard assets which could have been mangled?
Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#3I wonder what was the design consideration there? If I'd to make a guess, the point of having key in a re-programmable memory (susceptible to such errors) could be that it could be re-programmed later - otherwise it could've been just hardcoded in ROM. Athough if the error was that it was a RAM copy of the key that's got corrupt, this might explain things - no one to reboot the machine around, huh. If re-programmability was a design consideration, it is interesting is that there was no key reset procedure (with another, "master" key) which is something one would want to use if the normal communications key is compromised or corrupted.
Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#4That's pretty fascinating. I admit I find it kind of strange that only the encryption key was affected in this way, i.e. that finding the newly-correct key proved a fix to the issues, as opposed to fixing one issue out of many linked to such an event. It made me wonder--what are the odds of that? What is the relative exposure area of the encryption key compared to the rest of the onboard assets which could have been…
There's basically two things that happen with radiation in orbit.
* Ionizing dose weakens and disrupts crystalline structure. Wears things out / degrades their specs.
* Single, very high energy particles-- e.g. protons-- come in at high speed and change a voltage somewhere. This can have massively bad effects (e.g. it can, for non-radiation hardened parts, cause parts of the chip not meant to be a transistor to become one shorting power and ground-- this is a "single event latchup"). Or, it can affect the operation of one or a few adjacent bits of memory ("single event upset").
Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#5That's pretty fascinating. I admit I find it kind of strange that only the encryption key was affected in this way, i.e. that finding the newly-correct key proved a fix to the issues, as opposed to fixing one issue out of many linked to such an event. It made me wonder--what are the odds of that? What is the relative exposure area of the encryption key compared to the rest of the onboard assets which could have been…
It probably wasn't the only thing affected. It's just flipping bits in encryption keys has much more dramatic and obvious effect than flipping other random bits in memory. Flip a bit in a raster image and you get one funny-looking pixel. Flip a bit in an AES key and you completely corrupt all the data handled by that key.
Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#6Besides hardware mitigations (radiation hardening, ECC memory) what would be software mitigation techniques for this?
Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#7Besides hardware mitigations (radiation hardening, ECC memory) what would be software mitigation techniques for this?
Forward-error correction.
At the simplest, write the key ten different places in memory and compare the read values to determine the most probably correct.
Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#8Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#9From the headline I imagined this was something like "We lost our encryption key for some important data, but the NSA had already cracked or stolen it, so they were able to return it to us"
Re: Calling NSA to find your encryption key after a few bits were flipped (2010)
#10Why is traffic from Voyager even encrypted? The results back are public scientific data anyway, right? And it's not like other nations (the only ones with power to transmit that far, back then) would send rogue commands without getting caught.