There has recently been some discussion about using DNA simulations to encrypt; see this technical report and subsequent discussion here and here. The basic idea being proposed is to simulate biological processes in order to encrypt; more specifically, the process by which mRNA is generated from DNA. The entire report is strange. First, its entire presumption is that we need new methods because modern cryptographic algorithms keep getting broken. This is the same argument made in favor of quantum cryptographic schemes (like quantum key exchange). However, at least these quantum methods have a strong theoretical basis and achieve proven information-theoretic security (meaning that even an all-powerful attacker cannot learn the exchanged key). In contrast, this report just uses computational methods based on what happens to DNA. Why is this supposed to be any better than any other computational methods that we use today? On the contrary, there is no evidence whatsoever that it is hard to invert the scheme, and in fact, the authors admit that they themselves know of weaknesses (and suggest vague solutions for fixing them).

In addition to the above, the report ignores the fact that the cryptographic playing field is not even. It is true that our hash functions are looking weaker than ever before. It is also true that we are constantly on the lookout for new asymmetric schemes due to the need to use larger and larger keys all the time (even though RSA with long keys is still very safe). However, this does not mean that we don't have good symmetric encryption schemes. The opposite is true! It is well accepted that we know how to construct excellent block ciphers. 3DES has not shown any weaknesses in over 2 decades; AES remains extremely strong after almost a decade of intensive analysis. These schemes are quick and highly secure. The fact of the matter is that we don't need any new symmetric schemes at the moment (personally, I don't think that quantum key exchange is needed either). Moreso, what we definitely don't need are suggestions for schemes by non-experts with no reasoning as to why they should be better. (I know that I sound like a snob now. But cryptography in general is excruciatingly hard to get right and constructing a secure symmetric encryption scheme is even harder. There's just no reason to do it today even if you're an expert. Needless to say, if you're not an expert with years of experience in cryptanalysis you shouldn't try. However, for some reason, everyone thinks that it's easy to encrypt. Just mix things around a lot and it's got to be hard to break; right?)

A final caveat. I may be completely wrong. It's possible that all of our encryption algorithms have been broken by secret organizations out there. However, I highly doubt it. Although I assume that there are some things that are known to some of those secret organizations that we don't know in the open crypto community, I am very skeptical that they are earth shattering...

Self-encrypting hard drives are becoming a reality. One standard, led by the Trusted Computing Group, has been adopted by a number of vendors; see the press release here. I like this initiative a lot and really consider it a win-win situation. The cost of encryption is virtually nill because the encryption itself takes place in hardware on the drive. This means that everything is encrypted by default, without compromising performance. Note that this is a huge advantage. We may remember to encrypt our most sensitive files, but at the same time forget to encrypt our email archive, previous versions of the sensitive file, and of course the swap and hibernate files which can contain everything. Encrypting everything by default protects us from these omissions.

How secure are these drives? Well, the encryption keys are generated and stored internally on the drive. Thus, the security of the system depends on the security of the key inside the drive. This means that the main question to ask encrypted-drive manufacturers is how is the key stored inside, and how secure is it? If a secure smartcard chip is used, and the key is password protected, then this is great. If the key is obfuscated and somehow hidden (of course, and still password protected), then someone stealing the drive can probably get to it given enough effort. However, you have still made their life difficult and they have to take the drive away with them (it's unlikely that they'll be able to do this without taking the drive apart). So, in any case, you have gained a lot. (I am ignoring the possibility of really bad implementations, although experience tells us that this can also happen not too infrequently...) It is worth noting that highly sensitive files should probably still be encrypted on a higher level (using an encryption key that is stored in a separate smartcard that you take with you). Keeping the encryption key in a completely separate place is always the best practice and prevents even the most concerted efforts to decrypt.

On a usability note, since the encryption keys are internal to the drive there is no key management issue. This is good because key management is often the biggest hurdle to adoption. Regarding data loss, it is important to realize that if the encryption key is somehow lost due to a fault in the drive, then this would be the same as if your hard drive was completely destroyed. So it's important to also ask manufacturers what sort of fault tolerance has been built into the system regarding the encryption key. Needless to say, you should backup your files anyway (even if your hard drive is not encrypted).

A while ago I wrote about software-independent voting mechanisms. The basic idea is that a paper trail exists to enable verification of election results. (More specifically, a way that this can work is that a voter's choices are printed out, verified by the voter, and then placed in an old-fashioned ballot box. Then, a random sample of the voting stations are checked - counting the physical votes against the tally given by the voting machine on site. The number of ballot boxes that need to be counted can be mathematically computed to give a very high level of confidence. Without getting too bogged down in details, this number is not too high and is a function of the gap between the winner and loser.) 

This methodology is necessary because software is simply not reliable enough by itself. An argument against a paper trail is that audit logs record everything and so this suffices. This argument is weak because (a) the audit record may be incorrect to start with, and (b) something else can go wrong. Well, (b) happened! It turns out that Diebold's voting machines have an interesting "feature" - a delete button for erasing audit logs. Do we need any more proof?

I spent last week at BlackHat in DC. As usual, I really enjoyed it. There were many really great technical talks. My favorite was a talk entitled "Attacking Intel® Trusted Execution Technology" by a team at the Invisibility Things Lab. One of the reasons that I really liked this talk was because it presented results from an in-depth, long research project. These are not researchers who were looking for a quick way of getting a catchy title out there. They painstakingly studied the new Intel infrastructure and came back with good and bad news. The good news: this is really the right direction, and Intel has made a great contribution with this technology. The bad news: there are still problems, and in particular, it is possible to attack the secure loading process. This is also a great differentiator: rather than blasting Intel over the security flaw, the researchers gave an objective overview and gave both praise and criticism.

This is what great research is all about. Take the time to carry out an in-depth study on an important subject and then report the results, both good and bad. This team did a great job, and it showed. Their presentation was well accepted and appreciated.

Just one more comment: there were many other great talks at BlackHat that also presented high quality research, so my above statement is not to the detriment of anyone else.

We amuse ourselves with stories of laptops, backup tapes and flash drives containing sensitive information being lost or stolen. We ask ourselves how people can be so careless and negligent with such sensitive information. However, the truth is that stories like this will continue to happen, even when top secret information is at stake (see this recent story about a US army data leak, and this story at NetworkWorld for some interesting losses in the past year). The reason that I claim that this is inevitable is that there are simply too many people out there who handle sensitive data. Thus, even if we manage to reduce the probability of a leak to be very very small, the chance that there will be data breaches of this kind is still very high. In fact, if you're in a midsize company, the chances of a data breach of this kind happening to you within the next few years is also not very low. So what should you do?

Well, to quote the boy scouts, my conclusion is just that we should "be prepared". This involves ensuring that we have backups in case data is actually lost, and making sure that all data on external devices like flash drives and backup tapes, and all laptops are fully encrypted. It's really not difficult to do this these days, so why not? It also greatly reduces your legal liability...