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Comment by rbcgerard | Hacker News Reader

"One key premise here seems to be that prior to the Snowden reporting, The Terrorists helpfully and stupidly used telephones and unencrypted emails to plot, so Western governments were able to track their plotting and disrupt at least large-scale attacks. That would come as a massive surprise to the victims of the attacks of 2002 in Bali, 2004 in Madrid, 2005 in London, 2008 in Mumbai, and April 2013 at the Boston Marathon."

https://theintercept.com/2015/11/15/exploiting-emotions-abou...

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This is always the part of the anti-Snowden case that baffled me. Those who seem to think that he alerted terrorists to the most secure means of communication seem to assume that, prior to the Snowden leaks, they were communicating by yelling really loudly across the NSA buildings. It's like they simply forgot about the biggest reason it took so long to find Osama bin Laden: he was so security-concerned that he used couriers and relays (which, counter to the broad narrative about the terrorist shift to security, actually cannot be decrypted)

I understand what you're saying, and I agree. But I think it might be a little disingenuous to use Osama Bin Laden's crypto practices as an example. I believe this is the more interesting story of what really happened with Bin Laden?

>Pakistan secretly captures Bin Laden by bribing tribesmen. The US finds out by bribing Pakistani officials. Further bribes with foreign aid money get other Pakistani officials to issue a stand down order. The SEALS swoop in unopposed but somehow still lose a helicopter. They kill a captive Bin Laden as part of a deal to avoid exposing Saudi support for Al Qaeda. The media gets fed a cover story about the compound being a command center. Some doctor guy becomes a scapegoat and vaccination programs are derailed in all of Pakistan. The CIA fabricates documents from the compound and flirts with claiming credit for "enhanced interrogation" technique in the matter.

If you don't like that story then sure by all means stick with Story A: The CIA does brilliant investigative work. The commander-in-chief makes a gutsy call. The SEALs storm in and kill the bad guy in a firefight. He is buried at sea with full rituals. The 2012 presidential campaign starts a few days afterwards.

If you support Story A, then this would certainly make sense:

>It's like they simply forgot about the biggest reason it took so long to find Osama bin Laden: he was so security-concerned that he used couriers and relays (which, counter to the broad narrative about the terrorist shift to security, actually cannot be decrypted)

##EDIT

Claims comes from a previous HN article about the Killing of Bin Laden: https://news.ycombinator.com/item?id=9520984

Those are some pretty big claims, have any evidence to back them up?

The less evidence and the more faith involved, the more captivating the conspiracy theory. That's how they work.

The only thing that lends credibility to the story in the post you're responding to is the person who's claiming it's the truth. Seymour Hersh [1] has enough of a track record that we shouldn't dismiss it out of hand. As far as evidence goes, I'm not sure the official story has been proven any more than Hersh's story has, so it's hard to know what to believe.

[1] https://en.wikipedia.org/wiki/Seymour_Hersh

This IIRC is essentially the story reported by investigative journalist Sy Hersh, relying on unnamed sources. See here for the full read: http://www.lrb.co.uk/v37/n10/seymour-m-hersh/the-killing-of-...

Thank you! Ok I remember when that story broke but I didn't read the details. Seymour Hersh is such a respected and renowned journalist who has a track record for revealing exactly this stuff. But the lack of openness in the sources is disquieting. But the story is so odious and so serious, I suspect there are no sources that could weather the storm regardless.

I fail to see how story b contradicts the parent post. If Osama was easily traceable there was no need to bribe everyone.

The other 'wild' claim I heard was that his compound was actually a prison, built especially to house him. Again no proof, but an interesting idea none the less.

To be fair, an ultra-secure compound that the owner/resident of doesn't ever leave for fear of his own safety can be indistinguishable from a luxury prison in terms of outcome, even if it wasn't intended that way.

I was just using it as an example of it long being on the mind of terrorists that they need to take extreme precautions to avoid their electronics being compromised. Snowden didn't alert them to the concept of decryption. Sorry if I implied anything more.

The most dangerous terrorists have probably already reverted to couriers with one-time pads. One-time pads are uncrackable, yet they were used extensively before modern cryptography was even invented. They're cumbersome and constrained but very effective. No amount of mass surveillance will alter their efficacy.

https://en.wikipedia.org/wiki/One-time_pad

So I read the wiki on the One-time pad and there's something I'm a little stuck on. There's a statement (paraphrasing) that the OTP is immune to cryptanalysis (brute force) because any given key translates to all possible plain-text, and the viable words all have a-priori the same likelihood.

The thing I'm stuck on though, isn't it still possible to do semantic analysis on the various permutations. Basically reading permutations for cogent statements? So do some sort of a-posteriori analysis

Infeasible for a human to do, but assuming one could construct a significantly advanced parser (non-trivial of course), wouldn't it be possible to brute force still? What am I missing?

The key is the same size as the message. Each letter translates the corresponding letter and no others. You could make a key to translate the message to anything with the same number of letters.

The message has an equally probably of decoding to ANY message. You essentially have no information to work with.

Well no. What you are describing is basically searchig through all permissible permutations in a given search space, i.e. a thousand monkeys with typewriters. Fron time to time the system will produce something that is not gibberish, but there is no way of knowing if it is related to the true message at all.

No. What you described will work for a simple substitution cypher, but not for a one time pad. A one time pad is the same length as the message, and permutates every letter independently. Trying all keys will yield every possible plaintext. For example the phrase:

"The swallow flies at midnight"

May (with a one time pad) be encrypted into

"WD4oXOl8yO0QtD4sOf7ip0P7ScIia"

(which, incidentally, is indistinguishable from random noise)

If you just bruteforced that by xor'ing every character with every other possible character you could derive every possible message of that length, such as:

"garfield hate lasagna someday"

"men are cats why even bother?"

"pocket knives go to space yay"

etc ad infinitum

No measure of semantic analysis will help you here!

Ahh yep, got it.

Easy to tell the right sentence because it's the only one capitalized correctly! /s

Well-known caveat for people who are familiar with encryption, but it's worth calling out explicitly here:

If you use the same one time pad to encode two or more different messages, then all the sorts of attack proposed here become plausible again.

The security provided by a one time pad relies entirely on the fact that it is only ever used once.

I'd like to add this scenario actually happened during the Cold War. Soviets were reusing one time pads and the US army decrypted some of the messages, among other things this lead to discovery of Soviet spies targeting the US nuclear weapon program https://en.wikipedia.org/wiki/Venona_project

https://www.youtube.com/watch?v=yxx3Bkmv3ck

Computerphile recently showed how this was done.

Is it really still a "one time pad" if you used it multiple times?

I am out of my element here, but my understanding is that since the key is equal in length to the message, there is no way for you to know whether you are simply seeing a pattern in the key or a pattern in the message.

Imagine a one time pad made for encoding numbers that used a "MOD 10" operation on each digit.

Then imagine the key is:

    6926560279774

And the message is:

    0000000000000

The output is:

    6926560279774

Alternative messages:

    1234567890123 -> 7150027069897
    1111111111111 -> 7037671370885

In all cases, the patterns that you can discern may be from my message and may be from the key. As an analyst, you can't tell.

If this were English letters rather than numbers, and you know 'e' is very common, you still can't get anywhere because each 'e' is encoded with a unique character from the key.

This is a good description, but to add on to it: If there is a pattern in the plaintext, it does not increase the probability that there is a pattern in the ciphertext. It is true that there may be patterns in the ciphertext, but they give you no information about if there is a pattern in the plaintext.

It doesn't seem very likely that anyone has broken a modern symmetric cipher like AES or ChaCha. If not, a small random key is just as good as a one time pad, and you can reuse it for as many messages as you want. The bigger risks are that you reveal the key or that your hardware is evil, but OTPs don't save you from either of those.

With public key crypto it's a lot more likely that something might be broken. But then again if you somehow solve the problem of swapping secret keys/OTPs with everyone you want to talk to, you don't need public key crypto.

It's even more absurd than that. The premise is that we can have a public worldwide debate that emphasizes how important encryption is to successfully carrying out terrorist attacks, convince the world to give up their privacy for the sake of safety, and after the majority of the protestors have been defeated by public awareness that encryption and terrorism go hand-in-hand, the terrorists will go back to using phone calls and unencrypted email.

If (almost) everyone who is not a terrorist were to give up encryption, then it would be much easier to track down/narrow down the terrorists if they keep using it, no?

I don't think so, as far as I know encrypted data doesn't really have a signature that can be easily spotted

It does, it looks random (hight entropy).

Yes, measured data and unmarked compressed data have this same property, as do actual random data. But is does not look like 9 nines of false positive rate are a concern to those people.

You can set the entropy to any amount you want. You need to consider encryption methods that put in at least a bit of effort to hide themselves. It could select random phrases and pretend to be a spambot.

Or it could look like the output of a Markov chain sentence generator on the topic of religion and post the messages in some well-known forum.

Well, where's the boundary between cryptography that hides itself and stenography? Is there one?

If you include stenography, yes, it's certainly not easily recognizable. I don't think good stenography can be recognized at all, but that's not my area and I've got people contradict me at this (without further info), thus I'm not sure.

There's not much of a boundary, but that wasn't exactly the point I meant to make. You can do something like encode as ASCII 0s and 1s and have low entropy without that hiding anything.

No because they're not using it in the first place. It's a totally unrelated issue, dear to some for reasons entirely their own. The fear of terrorism is just a convenient little button to press to get their cookie.

Indulging this fantasy, it begs the question of whether those (enencrypted) communications would have been targeted and flagged for analysis

How does it beg the question?

There is no truth being asserted in the premise causing the conclusion to be true. It's fairly clear that it was a statement from an original source, that source being trustworthy is where we would find (or not find) the information which would show the conclusion to be true, not the premise of the 'fantasy.'

Give it up. In 30+ years of learning English, the only times I've ever seen it used in that sense has been when someone is being a pedant on forums and illustrating the now rapidly outmoded meaning of the phrase.

In 20+ years of learning English I've heard it used several times to refer to an obvious question or lack of information

"$noun did $verb which resulted in $result and $result is $something interest which begs the question $question."

well, your confusion of tenses kinda colors your knowledge about grammar rather questionable and i say that as a foreign speaker

Until it changes meaning, I cannot give it up. A curse I tell you!

Maybe, but I'd rather not send my financial information over the Internet in cleartext every time I buy something from a web site.

You wouldn't.

The government would just have the private keys so they could decrypt traffic easily.

Kind of like the TSA approved locks for your baggage. Those are very secure and can be opened only by the government officials, last I heard. The only downside is that those TSA master keys might become available to the third party somehow, but I don't see that happening anytime soon, since we can always trust the government to keep such information secure.

Not "might become available", they already are - https://github.com/Xyl2k/TSA-Travel-Sentry-master-keys

Someone posted a photo of master keys and Internet was, as usual, the Internet.

Call me crazy, but I think that may have been the joke.

No lock is secure, ever.

If there was some way to learn the identity of said terrorist simply by observing the origin and destination of an encrypted message, then perhaps. It would possible for them to coordinate and avoid this outcome. And there are still plenty of secure crypto systems out there so we wouldn't be able to decrypt their messages (unless quantum computers turn into an actual thing).

Not really, because the proposals aren't to go to no encryption but to go to government-backdoored encryption. To an observer you've still just a random stream of bits until someone tries to decrypt it with the backdoor key. Pretty easy to hide in unless we're monitoring every message.

And terrorists would be smart - they'd employ non-backdoored encryption, hide that in "legit" communications, and encrypt that with the proper back-doored government encryption. They'd appear to be a totally normal snapchat user, or whatever.

If we actually meant to give up all encryption, card-kiddies would destroy civilization in three weeks.

And when the next Snowden publishes the global decryption keys we'll all just update our software together.

Surely you mean "the next Impact Team" (those behind the Ashley-Madison breaches) because Snowden actually went through painstaking lengths to not reveal stuff that would put the public at danger like that.

Then the terrorists would just use non-encrypted communications and blend in with the massive flow of everyday data...

...Unless you're intercepting and sniffing everything that's unencrypted. Then we're back to square one.

> It's even more absurd than that... after the majority of the protestors have been defeated by public awareness that encryption and terrorism go hand-in-hand, the terrorists will go back to using phone calls and unencrypted email.

I think you're straw-manning their position here.

The opponents of encryption aren't claiming terrorists will start using unencrypted communication, they're advocating for legally-mandated "back doors" to be built into supposedly-secure communication systems.

It's not a straw-men. It's not of the problems with the rationale.

Terrorisms won't use legally-mandated software for they illegal operations.

You're right, but I didn't mean only phone calls and unencrypted email. I considered adding "or their equivalent back-doored technologies," but I hoped it would be clear. Using a compromised technology is the equivalent of unencrypted email and phone calls to whoever has the key. All it does is draw attention to how important it is to communicate in secret. This will be the Streisand effect of crypto.

How would they know, though? For all we know, OpenSSL has been backdoored in some subtle way.

My thought is that if we implement a back door policy, the public will have communication links which are much easier to compromise by any party, while terrorists can still easily use encryption and/or steganography to secure their communications.

All the back doors accomplish in the end is harming the general public.

Indeed. Also, combine your steganography argument with this image

http://www.friendmosaic.com/images/example-mosaic.jpg

and it's pretty easy to see that this avenue of thought --- that we will put our efforts toward finding a way to ban encryption --- is totally ridiculous.

It's not just that federally-mandated backdoors increase the chance of compromise (although they certainly do). If the U.S. government can mandate that technology companies provide access through encryption, then so can other countries. Sovereignty is still a powerful concept under international law.

So imagine if Apple, upon condition of selling iPhones within China, must provide the Chinese government with a backdoor through Apple's encryption. Do you know how many federal employees use Apple technology? Including the President himself, who totes an iPad everywhere?

I don't think that federal intelligence and law enforcement officials calling for backdoors have fully thought through the consequences.

> I don't think that federal intelligence and law enforcement officials calling for backdoors have fully thought through the consequences

I think assuming that level of incompetence is a big claim.

It's simply much more likely that the actual plans/goals and the talking points and press releases about the plans/goals are mostly unrelated, as usual. You can infer that those calling for backdoors have decided that calling for backdoors is the best thing to say, inferring anything more requires more information.

> I think assuming that level of incompetence is a big claim.

Not really. Have you listened to the average member of Congress lately? Incompetence runs deep throughout all levels of government.

I think largely politicians are very intelligent and competent. What they're not though, is open about their own thoughts. That's not their job. Their job is to reflect what their supporters (financially and votingly) want. If their supporters have wild nonsense ideas, they have to promote those ideas to keep their job. That's why they were elected. We don't choose politicians because they're smart and have good ideas. We choose them because they tell us our own foolish ideas back to us.

The best salesman is someone who believes in the product. I'm willing to take them at their word.

They key point here though is that their "supporters" are NOT the American public. They are private corporations and banks with their own agendas, usually contrary to the public's well being.

It's not fair to say incompetent; I didn't say that.

Instead, look at it this way: everyone has their area of responsibility. The head of the CIA is charged with providing the best possible situational awareness for the U.S. government. He's going to make proposals and requests that will help him do that.

He's not charged with balancing all possible consequences from his requests, and he's not going to do so.

> He's not charged with balancing all possible consequences from his requests, and he's not going to do so.

But ... that seems like quite a level of incompetence for someone trusted with the position of Head of the CIA?

By which I mean, not charging him with that responsibility is a mistake (in gov structure), but him actually not doing so is his own incompetence, is it not?

> You can infer that those calling for backdoors have decided that calling for backdoors is the best thing to say, inferring anything more requires more information.

How is calling for a really bad idea because it's the best thing to say different from the level of incompetence you say is too big to assume?

It sounds like the implication is that the politicians are smart enough to know that the backdoors are ultimately not going to happen but that calling for them is a way to appease voters who haven't followed this through to its logical conclusion.

edit: "not going to happen" could be read as "not going to be effective." I wouldn't actually be surprised if the US ended up passing some law restricting crypto to an approved list of backdoored schemes (surprised: no, dismayed: yes), forcing people into hiding their crypto in deniable ways. What some people don't seem to grasp is that no matter how much you outlaw certain math operations, whether or not the end users comply with those laws is ultimately up to them, and the terrorists simply won't comply.

I think assuming that level of _competence_, at least in fields other than diplomacy and public speaking, is a big claim. It's not reasonable to assume that every single ancient senator that's pushing for this is fully aware of the consequences, but it is reasonable to think they simply haven't thought any further than "I need to make it look like I'm doing something, or I'll look bad".

To a man with a hammer, everything looks like a nail. To a man who only has words, everything looks like a soapbox.

It would help conventional law enforcement. Most violent criminals probably don't put enough forethought into their spontaneous attacks to properly avoid notice by the NSA. Unfortunately the NSA doesn't seem to use their resources to secure the nation, and just ignores all the large scale violent crime that goes on daily.

It's largely outside of the NSA mandate to monitor the communications of US citizen criminals. It is not the fault of the NSA that Congress has not passed a law telling them to spy on domestic criminals.

I get that some of the controversy lately is about how well they stick to their mandate, but that doesn't change what the mandate is.

> Unfortunately the NSA doesn't seem to use their resources to secure the nation, and just ignores all the large scale violent crime that goes on daily.

The NSA is part of the Department of Defense charged with foreign signals intelligence for national security purposes, its not a law enforcement agency. (And many of the tools it uses would be flagrantly unconstitutional if used for domestic law enforcement.)

Generally, blurring of the military and law enforcement roles is not a healthy thing; it may be good for order, but rarely for liberty.

One of the reports on the Osama Bin Laden raid stated that he had a porn stash, I wondered at the time if this was for use as a starting point for steganographic communications.

Many regulations do. The real trick is giving even the terrorists reasons to behave.

It sounds impossible, of course, but that's just because we're not sure where these guys put their goals; some may be fighting for lack of another purpose in their life, while others may be motivated by personal loss or a thorough belief in the violent interpretation of Islam.

So what we really need to do is find a common thread among all the terrorists, and pull on it.

The State is far more efficient and effective at instilling terror than any loose organization of dissidents could ever hope to be.

Read pretty much anything Amnesty International publishes, or even the right history books and you'll have all the evidence you ever need as to why privacy is important even when you think it isn't.

Once bad things start happening it's too late to change your mind. They already have what they need.

ISIS actually tweeted in the clear before this one. Forget crypto, nobody was reading the open sources even.

http://www.news.com.au/world/europe/islamic-state-tweeted-of...

I don't fully understand this line of thinking. To me, it's like saying "The belief that seat belts save lives might come as a surprise to these people who died in automobile accidents while wearing seat belts."

It may indeed be that this kind of signals intelligence isn't actually helpful, but I don't think this is a very good argument either way. If there was a massive disruption of planned terrorist attacks, it is not useless just because there wasn't a complete elimination of terrorist attacks.

Exactly. Same reason you have locks on your doors even though they are easy to defeat. Tech types want to believe that the government is always overreaching and everything is a slippery slope to some other loss of freedom. Mixed in with a bit of overcooked paranoia thinking the government has enough time and energy to track down everyone and whatever laws they are breaking by reading their emails.

If they actually did have enough time to enforce all broken laws by reading our emails then their unreasonable effectiveness may warrant the intrusion. If these capabilities only are able to thwart a small percent of lawless plots then perhaps the cost to our personal privacy and security is too high to justify.

Bad analogy. The sites I help run are often receiving 10k attacks per minute with fuzzers and known exploits. The internet provides anonymity unlike some guy standing at your front door. I have yet to have an army of bad guys trying to pick my lock 10k time per minute on my house. Backdoors into things are economy is based on SSL etc. are just plain irresponsible.

The terrorists also utilized roads and clean drinking water... better get rid of those, too!

This argument misses the point IMHO: the US government was investing astronomically large sums of money in an infrastructure that was fated to quickly become less and less effective. In doing so, they were even willing to violate basic constitutional rights.

It would indeed come as a massive surprise to the 2008 Mumbai terrorists, who were well versed in in using encrypted channels to communicate --

http://www.nytimes.com/2008/12/09/world/asia/09mumbai.html?_...

It was sarcasm. Encryption was used in all the listed attacks.

They were not using encrypted channels for their operational control. The security forces had no trouble listening in on the calls and text messages being sent between the attackers and their command and control infrastructure.

The issue the security forces _did_ have was in identifying where the calls were originating. The actual content was not encrypted though.

I think I remember a terrorist attack in 2011 too.

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