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Crypto Snake Oil
An anonymous reader writes "Luther Martin of Voltage Security has published an article about the perception of cryptography today with regards to quality and honesty in vendors. From the article: 'Products that implement cryptography are probably credence goods. It requires expensive and uncommon skills to verify that data is really being protected by the use of cryptography, and most people cannot easily distinguish between very weak and very strong cryptography. Even after you use cryptography, you are never quite sure that it is protecting you like it is supposed to do.'"
Snake oil is a traditional Chinese medicine used for joint pain. However, the most common usage of the words is as a derogatory term for medicines to imply that they are fake, fraudulent, and usually ineffective. The expression is also applied metaphorically to any product with exaggerated marketing but questionable or unverifiable quality.
'nuff said
Even though in many cases this might be true, and product prices are increased because of it, weak encryption is a lot better than no encryption at all. There are many people out there who might go as far as casual data theft (eg; taking someone at their school's USB memory stick), but even a weak layer of encryption will stop all but those who know what encryption is and where to start breaking it.
Warhammer forums
If you are worried about the honesty of vendors, this is exactly why you should be using free cryptography software in the first place, because you know that is going to be strong, and trustworthy, because otherwise someone would have changed it by now. :)
It is also much easier to verify strength by reading the source rather than by reading the binary or by cryptanalysis.
So, for example, with a post like this, will somebody in a dark suit and glasses show up at my door tomorrow?
c id=15899118
Blasphemy #1: I've heard from a claimed friend of one of the inventors of RSA that it was cracked it years ago. Yet, it continues to get worldwide use. Sure my friend was probably full of it... but who am I suppose to trust here? The government?
Blasphemy #2: One of my close friend's mother had to switch fields from Numerics after she published some papers considered too sensitive. It had something to do with factoring.
Blasphemy #3: Anybody else notice that quantum computers have been proven to be capable of factoring really well, but no one has shown that they can solve any NP-hard algorithms? Come on... factoring isn't NP hard.
Then, there's just some silly stuff I've noticed about crypto. Why do we always seem to use encryption just a generation or so ahead of what is needed to crack it? SHA-1 for example... And, why do we encrypt one small block at a time. Each encrypted file usually gives many independent chances to crack the key, and in many cases, some of those blocks have known data. Also, public key is great, but secret key can be easily shown NP-hard to crack (in terms of secret key length) with semi-reasonable assumptions, while public key has no such simple proof. I personally have been trying to prove that no public key system can be NP-hard, but what the heck... I'm not that good. However, I do believe it's probably true.
It seems any time you start talking about crypto, you get assailed by experts telling you just how full of it you are. Consider something simple, like generation of random numbers. Just claiming you can do a good job brings nay-sayers out of the woodwork. See:
http://linux.slashdot.org/comments.pl?sid=193904&
http://www.billrocks.org/rng
for how to do it well. Any child could do it (well at least my geeky 6-year-old).
Everything about crypto is scary... Are we being manipulated into using weak encryption? Is there some invisible line, which if crossed, bad things can happen? The scary part is the unknown.
--
Just because your paranoid doesn't mean the world isn't out to get you.
Beer is proof that God loves us, and wants us to be happy.
Many Slashdot readers are savvy enough to know that when a software product advertises itself as using, say, secret encryption algorithms with 10,000 bit keys, it's probably snake oil. But I'm seeing increasing amounts of snake oil that uses the Advanced Encryption Standard, AES, and it can be just as weak.
AES itself of course is nigh-on as trustworthy a cryptographic primitive of its kind that we have. But just because you've used the right primitive, doesn't mean you've built a secure product. You have to consider what chaining mode to use, how to handle passphrases if they exist, how to keep your secrets secret, defense against side channel attacks, and more.
What I look for is a product that provides enough information that I can actually assess its security - what attacks they've considered and how they've built the product to defend against them. What I see disturbingly often is a bald declaration that the product is secure, because it uses AES.
Xenu loves you!
>> It requires expensive and uncommon skills to verify that data is really being protected by the use of cryptography
No. It requires reading a couple of good, inexpensive books and understanding of what the heck you're doing. Math behind the whole thing can be complicated. But you don't really need to understand the math 100% here. All you need to know is whether an algorithm is considered "strong" by today's standards, understand a few key concepts, guard your keys, and aproach security related coding with a healthy amount of paranoia.
In other words, a decent developer can get a pretty good understanding of this all in two weeks or less. And these skills need to become "common" already.
If you believe that, no wonder so much insecure stuff is being written. I have been called upon to review code written by developers with your level of knowledge in crypto. They do things like use RSA without proper padding, or use predictable IVs in CBC mode, or fail to properly authenticate the message. They also add totally unnecessary complexity to the system in the mistaken belief that their improvements make it more secure. I shudder when I see a copy of "Applied Cryptography" on the shelves because it is just enough knowledge to be dangerous.
Even the experts make errors in cryptographic protocol design and implementation - I've been doing this for ten years and I've made at least one howler myself. Why do you think, contrary to the advice of pretty much everyone who really knows their stuff, that people with a couple of week's worth of knowledge can get this stuff right?
Xenu loves you!
Products that implement cryptography are probably credence goods. It requires expensive and uncommon skills to verify that data is really being protected by the use of cryptography, and most people cannot easily distinguish between very weak and very strong cryptography.
Can you distinguish, by inspection, between a reliable automobile and a piece of junk that will barely last 2 years? I certainly can't. So I rely on reviews by people I trust when I buy a new car.
In the field of cryptography there are several people who have written peer-reviewed books about cryptography, are trusted in the community, and who occasionally review products. Bruce Schneier is one (there are others, use Google, this is not mean to be a puff for Schneier or his company).
There are also open-source cryptographic programs, which are peer-reviewed and definitely not snake-oil.
or you could just take the common sense approach and use products that rely on algorithms that are open, widely tested and reviewed, and known secure. Algorithms like Blowfish, AES, etc. I use Apple's built-in Filevault protection to encrypt my Powerbook's hard disk, in the event that it is ever stolen. It uses AES-128, which means I know that no-one is getting in without my password.
Any vendor that relies on a custom algorithm for their encryption technology shouldn't be trusted.
Get creative, use Rot-14 or something.
God spoke to me.
It's pretty well known that there are many snake oil products that deploy cryptography. Bruce Sneier frequently displays snake-oil cryptography products in his newsletter, for instance. And these are just the really obvious ones.
Some time ago, I tried to evaluate if a Enterprise Service Bus (intercomponent communication) was fit enough to be put into a production environment. It said that it had AES encryption build in. When I looked at the manual, it displayed a pop up window where you could choose the key-size. It listed exactly all key sizes that were *not* possible for AES. This was a very short evaluation, I can tell you. This also shows a very important thing about cryptography: the algorithms used say very little about the security of an application.
Generally, the manual for cryptographic services is easy to find. This is simply because cryptography is added at the end of the development lifecycle. This is logical because cryptography is not part of the main functionality of most applications (e.g. mime encryption in email products). It's something that was added after the products main functionality was finished. So just look at the last paragraph, or Appendix Z and you are looking at it.
Sometimes it is easy to see why so many products contain bad cryptography. Take XML signatures for instance. XML signatures themselves contain *references* to the data that is signed and the cryptographic techniques used. If you are to verify an XML digital signature, you *must* check if these are not altered. Furthermore, you must keep the XML schema-definitions on your own disk, and not retrieve them from the internet. Nevertheless, I've not seen any API-documentation even mentioning this rather obvious cryptographic insight. You can rest assured that there will be many implementations that will get this wrong.
Cryptography is hard.
The real insight of this story is the listing of the products into "credence goods". If you can call this new insight. Otherwise, it's just stating the well known/obvious.
This is something I've often considered about commercial encryption software. There's just no way to be sure of their validity, as they are closed source implementations. Open source solutions like Truecrypthttp://truecrypt.sourceforge.net/ are at least somewhat more trustworthy, in that they can be openly reviewed by anyone. Despite the fact that I know jack all about the specific math behind AES and such, at least I can read some simple explanations of the concepts, read the source, and decide if I want to trust my data to it. Honestly, unless we get down to the fraction of the population that actually does understand these bits at a deep level, that's the best any of us can do really.
Sure, large clusters of powerful servers working in tandem(or quantum computing) may render the factoral math behind crypto obsolete. A nice thing though, is that those kind of solutions are limited to those that can afford them. Still, even if it's all true, and I'm wasting my time encrypting things, what better solutions do we have?
Anyone remember the Blitzkrieg server, which seems like the solution to all of the world's security needs? The expression Bruce Schneier used was "just too bizarre for words". I don't know if this was an elaborate trolling attempt or an actual real honest scam to deceive the terminally dumb, but it's fun to read, still, just for the amazing technobabble and ludicruous claims.
So did he write the article and then post it on wikipedia, or did he swipe it from wikipedia and post on his site?
http://en.wikipedia.org/wiki/Snake_oil
Not trying to troll, I just couldn't figure out which it was and I don't have a lot of time to investigate.
Transporter_ii
Doctors destroy health, lawyers destroy justice, universities destroy knowledge, religion destroys spirituality
If you are truly concerned about the validity of cryptography provided by the vendor, then try to find products that have been certified under the FIPS 140-2 standard. The only problem might be that a lot of those products are usually commercial grade items meant for use by government agencies; however, some of the items that have received approval are reasonably available to consumers. The products are reviewed by independent labs, and then the CMVP reviews the labs results. (The site was down earlier this morning.)
These products have been reviewed by independent labs, who review their implementation to verify that cryptographic mechanisms are implemented properly. This includes reviewing source code and/or hardware designs. Just a thought for anyone who is truly concerned that their hardware or software be compliant. (Note: If you want a "secure" operating system, look into CC Evaluation.)
"Some days you just can't get rid of a bomb."
I worked for sevearal years on a programming language called REALbasic. In the latter releases that I saw, it featured "encryption". A compiler is basically a tool that takes human readable commands and turns them into a program that a computer can run. This process is not easily reversable, and once compiled, it's difficult at best to make changes to the progam.
Encryption was added to RB so that it was possible for you to give away portions of your program's "source code" (the human readable part) without anyone actually being able to READ it. They could incorporate your souce into their new project and use it normally, they could just not read it or make changes to it.
This sounds like a nice idea, until you realize that when you get someone's "encrypted" source code and add it to your program, the compiler has to be able to read the source code, because it needs to translate it for your new program. This means one thing: the encryption is not secure because the compiler itself must somehow posess a "master key" of sorts so that it can read the source code to do its thing. So... when you select the module and try to open it to look at it, it's not that it can't read it.. it's that it won't read it. A sufficiently skilled programmer could go into the compiler and flip a switch inside it and basically say "ignore that", and you would have unrestricted access to the so called "encrypted" informataion.
I assisted with a project where we found out how this information was encrypted. In short, a fixed key was used to encrypt the project data. Then a different fixed key was used to encrypt the passcode you would use to "protect" the project. Thus, the compiler could ask you for the password if you wanted to read your own project, and it could verify you typed in the correct passcode. If you did, it would decrypt the project for you to view. So you see, the compiler does not NEED the passcode, it simply WANTS it.
It took us about a week to write a program that would read in the projects, decrypt them using the fixed key and completely ignoring the passcode thing, and saved an unprotected naked project file that anyone could edit or view.
This is probably not too far from the mark on how a LOT of programs "protect your privacy". In reality they are only protecting you from the casual inspection. Anyone that really wants your data can get it, all too easily. Be sure that with any program you are certain that the program NEEDS the passcode to unlock your data. If it only WANTS it, (is there a password reset option available?) then you know it's "security through obscurity", and we know how totally worthless that is.
You thought your windows or OS X keychain was secure? You have auto login turned on? Does the computer need your password? Think about it.
I work for the Department of Redundancy Department.
One of the major perils facing a would-be crypto user is himself. Many people think they know it all (as evidenced in many of the posts to this article) and therefore can dictate insecure and plain silly design choices when deploying a secure solution in a non-trivial environment (for anything: authentication, the crypto itself, access enforcement, etc.).
For the vendor this creates a conflict. On the one hand, you want to satisfy the customer's request. On the other hand, you know your customer is shooting himself in the foot and very possibly becoming a vendor reputation problem later on down the line.
In my experience, most customers are accustomed to being "always right" and fail to recognize that crypto/security may be one of those things that they simply do not know enough about and to let the vendor help them. It is often the case that the vendor can explain/evangelize and detail the very attack the customer is opening himself up to with little or no effect - the customer is convinced they know it all.
Ok, I'll be fair - though God alone knows why, and I think even God gave up trying to figure out the tangled mess I call a brain some time ago. They did use DES - not triple DES, just plain DES - for the really really sensitive stuff. The encryption key was visible to anyone logged in on any account, however, as the DES they used required the key to be the first parameter and they made no effort to erase it. So it was technically encrypted. (Once the passkey has been broadcast to all and sundry, I do not regard the encryption as anything more than a technicality, and in the case of DES, I seriously doubt you could even claim that.)
I've heard that security has since improved. I say "heard", because it was some time AFTER security was said to have been improved that reports started coming out of a fileswapper using NASA storage machines as extra disk space - the very same organization and very same type of mass storage device I had serious doubts about many years prior to that.
But that's a Government institution! Yes, and they're the ones with a great many experts in such matters and a great many contracts with people who can not merely withdraw business but also guarantee a disaster in the next election. The bulk of private corporations out there have neither the skills to draw on OR the incentives to maintain some sort of standard. All they have to do is ROT13 and tell you it's got digital security. Enough suckers'll buy into it to keep the CEO in champaign, caviar and girls of commercially-negotiable virtue for life.
The problem is, there is no mandated minimum standard for security, so those who can WILL use the lowest standard possible that will deceive customers into thinking they're safe whilst staying a gnat's whisker (after being compressed by the forces of a neutron star) beyond what could be sued for in courts, assuming a technically ignorant judge.
IMHO, "snake oil" could be vastly reduced - not eliminated but reduced - by placing minimum standards for crypto, compression and other easily-manipulated areas of technology, and enforcing them. Not maximum - that's what the intelligence services want, and they want it to be zero. I'm strictly talking minimum. Your good, old-fashioned lemon law - does it fill the purpose for which it was sold to the customer? Yes or no.
In the case of cryptography, that would be rephrased as follows: would a reasonable person, aware of the strengths and deficits of the technique concerned, aware of any warnings published on the block crypto lounge, hashing function lounge, etc, aware of the Usenet Crypto FAQ (ie: aware of the "common knowledge" that exists on cryptography), and aware of the grade of security the user is demonstrably expecting, agree or disagree that the cryptographic system sold meets the grade expected or not?
If it does not, it is a lemon for the purpose for which it was sold. It might be perfectly good otherwise, but it doesn't, can't, and never will do what was expected of it.
This would be enforceable, as I said very clearly that I'm talking about weighing the "common knowledge" against the "personal expectation". Both are easy to define and even a non-expert should understand a skull-and-crossbones labelled "BROKEN, DO NOT USE" in a crypto lounge. They might not understand the fine nit-picking or the advanced maths, but that's why I'm sticking solely to what is commonly known and understood, not what is derivable from axiom 327 as applies to lemma 291 as described by Professor Branestawm's obscure paper entitled "techniques for splicing dormice genes into giraffe brai
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Because WPA is inconvenient when you're using a device that doesn't support it.
WPA-supporting devices are all but mandatory for laptops and WAPs these days. If your device doesn't support WPA, replace it.
These WEP is little more than a "no tresspassing" sign - it will keep people from accidently connecting to your WLAN, but not much else.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
If a million people read the code, and 1 in 10,000 were cryptographers who examined the code closely, that's still 100 cryptographers examining the code. Assuming most of them were working independently or in small groups, that's good enough for me. It's probably a lot better than a closed-source solution where maybe half a dozen experts looked closely at the code.
The best thing about open-source is that if it's a real concern to you, you can hire your own experts to check out the implimentation. You don't have to take the vendor's or anyone else's word for it.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.