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Inside the Operating System Edward Snowden Used to Evade the NSA

wired.com

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Re: Inside the Operating System Edward Snowden Used to Evade the NSA

#51

Post by bch »

> How do we now it isn’t some government plot designed to snare activists or criminals? A couple of ways, actually. One of the Snowden leaks show the NSA complaining about Tails in a Power Point Slide; if it’s bad for the NSA, it’s safe to say it’s good for privacy. And all of the Tails code is open source, so it can be inspected by anyone worried about foul play.

It does not follow that either, or both, of these points (Open source, an NSA complaint slide) make this "snare proof". I'm not saying that it isn't, but there is no logic in the Wired article's assertions.

Re: Inside the Operating System Edward Snowden Used to Evade the NSA

#52

Post by hackuser »

devconsole wrote: post #12

It's worth noting that Tails doesn't make you impervious. Tails uses Tor, and Tor is vulnerable to NSA and GCHQ attacks. Specifically, they have the capability of deanonymizing individual targets. I hypothesize that this capability works by monitoring Tor traffic worldwide, then performing a timing correlation between an origin and an endpoint. Here's an example: Let's say (for the sake of example please) that the NS…

> Tails doesn't make you impervious

For all X, X does not make you impervious. All it can do is increase the cost to an attacker.

Re: Inside the Operating System Edward Snowden Used to Evade the NSA

#53

Post by acqq »

dmix wrote: post #43

One important and often overlooked feature of Tails is when you shut it down it wipes your system memory/RAM using sdmem. Your encrypted data and sensitive files are often accessible via memory forensics even if you shut your computer down. Including the websites you visited. Your encryption keys can be in your computers memory for weeks and is easily accessible via a memory dump. This is why people say that with phy…

Data can be retrieved from DRAM not after weeks (your claim is "even if you shut your computer down (...) Your encryption keys can be in your computers memory for weeks") but only

http://en.wikipedia.org/wiki/Cold_boot_attack

"in the seconds to minutes after power has been removed."

The reason is explained here:

http://en.wikipedia.org/wiki/Memory_refresh

And even the electrons from SRAM, which doesn't need refreshes and which was for decades not used as "RAM" in the computers will leak away without the power:

http://en.wikipedia.org/wiki/Static_random-access_memory

"SRAM exhibits data remanence but it is still volatile in the conventional sense that data is eventually lost when the memory is not powered."

Of course, if you never power off your computer but just reset it (the power is never cut off) or if you shut it down and immediately power it up the content of the RAM can really survive for much longer.

Re: Inside the Operating System Edward Snowden Used to Evade the NSA

#54

Post by [deleted] »

acqq wrote: post #53
dmix wrote: post #43

One important and often overlooked feature of Tails is when you shut it down it wipes your system memory/RAM using sdmem. Your encrypted data and sensitive files are often accessible via memory forensics even if you shut your computer down. Including the websites you visited. Your encryption keys can be in your computers memory for weeks and is easily accessible via a memory dump. This is why people say that with phy…

Data can be retrieved from DRAM not after weeks (your claim is "even if you shut your computer down (...) Your encryption keys can be in your computers memory for weeks") but only http://en.wikipedia.org/wiki/Cold_boot_attack "in the seconds to minutes after power has been removed." The reason is explained here: http://en.wikipedia.org/wiki/Memory_refresh And even the electrons from SRAM, which doesn't need refreshes…

[deleted]

Re: Inside the Operating System Edward Snowden Used to Evade the NSA

#56

Post by unhammer »

im3w1l wrote: post #39
unhammer wrote: post #38

Earlier quoted context omitted.

You might want to run a non-exit node at your home. That way you have a lot of Tor traffic all the time, and the one time you really do need anonymity, it doesn't show up as anything unusual.

I don't quite know how this works, so forgive me if this is a stupid question, but couldn't someone just take the difference between your inbound and outbound tor traffic to find how much traffic originates from your computer?

If the in/out rate of your bridge was both constant And lower than the max in/out rate of your connection, but it seems a bit of a stretch.

(And of course they wouldn't know that it was your traffic to whatever site they're surveilling, they'd just have evidence that was not inconsistent with you actively using Tor to do Something Or Other at that time.)

Re: Inside the Operating System Edward Snowden Used to Evade the NSA

#57

Post by reedalex01 »

acqq wrote: post #53
dmix wrote: post #43

One important and often overlooked feature of Tails is when you shut it down it wipes your system memory/RAM using sdmem. Your encrypted data and sensitive files are often accessible via memory forensics even if you shut your computer down. Including the websites you visited. Your encryption keys can be in your computers memory for weeks and is easily accessible via a memory dump. This is why people say that with phy…

Data can be retrieved from DRAM not after weeks (your claim is "even if you shut your computer down (...) Your encryption keys can be in your computers memory for weeks") but only http://en.wikipedia.org/wiki/Cold_boot_attack "in the seconds to minutes after power has been removed." The reason is explained here: http://en.wikipedia.org/wiki/Memory_refresh And even the electrons from SRAM, which doesn't need refreshes…

The original cold boot paper was released in 2008 and they only demonstrated the attack on DDR2 memory [1]. A paper published in 2013 [2] discussed cold boot on modern hardware.

"This study is based on 5 different computer systems. While we demonstrate that simple warm reset attacks (not cutting power) are effective even against DDR3 systems, we were not able to detect any data remanence for DDR3 after cold boots. Even cooling the RAM chips did not reveal data remanence beyond cold boots. This leads us to the claim that cold boot attacks relying on RAM remanence beyond cold boots are not possible against modern DDR3 RAM chips."

[1] https://www.usenix.org/legacy/event/sec08/tech/full_papers/h...

[2] http://www1.cs.fau.de/filepool/projects/coldboot/fares_coldb... (search for DDR3 to find the relevant sections)

Re: Inside the Operating System Edward Snowden Used to Evade the NSA

#59

Post by bashinator »

SixSigma wrote: post #7

Even wired don't know what an OS is. Or rather the definition of OS has changed. A strange time when your industry jargon enters the popular lexicon but always slightly twisted. You can't even call yourself a Troll in the UK now without people thinking you go on Facebook and mock the dead to their nearest and dearest.

What is Tails, if not an operating system?

Re: Inside the Operating System Edward Snowden Used to Evade the NSA

#60

Post by joezydeco »

gtirloni wrote: post #55

And naturally, nobody knows exactly who created it. Shouldn't it be the opposite so we all know who we're relying on? It's the same question I'd throw at Bitcoin.

I think users would prefer that covert government agencies not know where to find the authors, either to avoid undue influence or surreptitious hacking of their development machines to insert backdoors and other nefarious things.

Plus, as TFA states, the code is all out there in the open and able to be reviewed. Does it matter who wrote it at that point?

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