World War I began in 1914 as a fight among several European nations, while the United States pursued a policy of non-intervention. In fact, Woodrow Wilson was reelected President largely because “He kept us out of war”. But as the war unfolded in Europe, an intercepted telegram sent by the German Foreign Secretary, Arthur Zimmermann, to the Mexican government inflamed the U.S. public opinion and was one of the main reasons for the entry of the U.S. into WWI. This is the story of the encrypted telegram that changed the last century.
People who have incredible competence in a wide range of fields are rare, and it can appear deceptively simple when they present their work. [Chris Gerlinksy]’s talk on breaking the encryption used on satellite and cable pay TV set-top boxes was like that. (Download the slides, as PDF.) The end result of his work is that he gets to watch anything on pay TV, but getting to watch free wrestling matches is hardly the point of an epic hack like this.
The talk spans hardware reverse engineering of the set-top box itself, chip decapping, visual ROM recovery, software reverse analysis, chip glitching, creation of custom glitching hardware, several levels of crypto, and a lot of very educated guessing. Along the way, you’ll learn everything there is to know about how broadcast streams are encrypted and delivered. Watch this talk now.
Some of the coolest bits:
- Reading out the masked ROM from looking at it with a microscope never fails to amaze us.
- A custom chip-glitcher rig was built, and is shown in a few iterations, finally ending up in a “fancy” project box. But it’s the kind of thing you could build at home: a microcontroller controlling a switch on a breadboard.
- The encoder chip stores its memory in RAM: [Chris] uses a beautiful home-brew method of desoldering the power pins, connecting them up to a battery, and desoldering the chip from the board for further analysis.
- The chip runs entirely in RAM, forcing [Chris] to re-glitch the chip and insert his payload code every time it resets. And it resets a lot, because the designers added reset vectors between the bytes of the desired keys. Very sneaky.
- All of this was done by sacrificing only one truckload of set-top boxes.
Our jaw dropped repeatedly during this presentation. Go watch it now.
Although I’ve been to several DEF CONs over the past few years, I’ve never found time to devote to solving the badge. The legendary status of all the puzzles within are somewhat daunting to me. Likewise, I haven’t yet given DefCon DarkNet a try either — a real shame as the solder-your-own-badge nature of that challenge is right up my alley.
But finally, at the Hackaday SuperCon I finally got my feet wet with the crypto challenge created by [Voja Antonic]. He developed a secondary firmware which anyone could easily flash to their conference badge (it enumerates as a USB thumb drive so just copy it over). This turned it into a five-puzzle challenge meant to take two days to solve, and it worked perfectly.
If you were at the con and didn’t try it out, now’s the time (you won’t be the only one late to the game). But even if you weren’t there’s still fun to be had.
Thar’ be spoilers below. I won’t explicitly spill the answers, but I will be discussing how each puzzle is presented and the different methods people were using to finish the quest. Choose now if you want to continue or wait until you’ve solved the challenge on your own.
If you’ve spent any time around prime numbers, you know they’re a pretty odd bunch. (Get it?) But it turns out that they’re even stranger than we knew — until recently. According to this very readable writeup of brand-new research by [Kannan Soundararajan] and [Robert Lemkein], the final digits of prime numbers repel each other.
More straightforwardly stated, if you pick any given prime number, the last digit of the next-largest prime number is disproportionately unlikely to match the final digit of your prime. Even stranger, they seem to have preferences. For instance, if your prime ends in 3, it’s more likely that the next prime will end in 9 than in 1 or 7. Whoah!
Even spookier? The finding holds up in many different bases. It was actually first noticed in base-three. The original paper is up on Arxiv, so go check it out.
This is a brand-new finding that’s been hiding under people’s noses essentially forever. The going assumption was that primes were distributed essentially randomly, and now we have empirical evidence that it’s not true. What this means for cryptology or mathematics? Nobody knows, yet. Anyone up for wild speculation? That’s what the comments section is for.
(Headline photo of researchers Kannan Soundararajan and Robert Lemke: Waheeda Khalfan)
There’s nothing more dangerous, so the cryptoheads say, than quantum computing. Instead of using the state of a transistor to hold the value of a bit as in traditional computers, quantum computers use qubits, or quantum information like the polarization of a photon. According to people who know nothing about quantum computers, they are the beginning of the end, the breaking of all cryptography, and the Rise of the Machines. Lucky for us, [Jean-Philippe Aumasson] actually knows a thing or two about quantum computers and was able to teach us a few things at his Shmoocon talk this weekend, “Crypto and Quantum and Post Quantum”
This talk is the continuation of [Jean-Philippe]’s DEF CON 23 talk that covered the basics of quantum computing (PDF) In short, quantum computers are not fast – they’re just coprocessors for very, very specialized algorithms. Quantum computers do not say P=NP, and can not be used on NP-hard problems, anyway. The only thing quantum computers have going for them is the ability to completely destroy public key cryptography. Any form of cryptography that uses RSA, Diffie-Hellman, Elliptic curves is completely and totally broken. With quantum computers, we’re doomed. That’s okay, according to the DEF CON talk – true quantum computers may never be built.
The astute reader would question the fact that quantum computers may never be built. After all, D-Wave is selling quantum computers to Google, Lockheed, and NASA. These are not true quantum computers. Even if they’re 100 Million times faster than a PC, they’re only faster for one very specific algorithm. These computers cannot simulate a universal quantum computer. They cannot execute Shor’s algorithm, an algorithm that finds the prime factors of an integer. They are not scalable, they are not fault-tolerant, and they are not universal quantum computers.
As far as true quantum computers go, the largest that has every been manufactured only contain a handful of qubits. To crack RSA and the rest of cryptography, millions of qubits are needed. Some algorithms require quantum RAM, which nobody knows how to build. Why then is quantum computing so scary? RSA, ECC, Diffie-Hellman, PGP, SSH and Bitcoin would die overnight if quantum computers existed. That’s a far scarier proposition to someone hijacking your self-driving car or changing the display on a smart, Internet-connected thermostat from Fahrenheit to Celsius.
What is the verdict on quantum computers? Not too great, if you ask [Jean-Philippe]. In his opinion, it will be 100 years until we have a quantum computer. Until then, crypto is safe, and the NSA isn’t going to break your codez if you use a long-enough key.
CSL Dualcom, a popular maker of security systems in England, is disputing claims from [Cybergibbons] that their CS2300-R model is riddled with holes. The particular device in question is a communications link that sits in between an alarm system and their monitoring facility. Its job is to allow the two systems to talk to each other via internet, POT lines or cell towers. Needless to say, it has some heavy security features built in to prevent tampering. It appears, however, that the security is not very secure. [Cybergibbons] methodically poked and prodded the bits and bytes of the CS2300-R until it gave up its secrets. It turns out that the encryption it uses is just a few baby steps beyond a basic Caesar Cipher.
A Caesar Cipher just shifts data by a numeric value. The value is the cipher key. For example, the code IBDLBEBZ is encrypted with a Caesar Cipher. It doesn’t take very much to see that a shift of “1” would reveal HACKADAY. This…is not security, and is equivalent to a TSA lock, if that. The CS2300-R takes the Caesar Cipher and modifies it so that the cipher key changes as you move down the data string. [Cybergibbons] was able to figure out how the key changed, which revealed, as he put it – ‘the keys to the kingdom’.
There’s a lot more to the story. Be sure to read his detailed report (pdf) and let us know what you think in the comments below.
We mentioned that CSL Dualcom is disputing the findings. Their response can be read here.
Imagine a world where the most widely-used cryptographic methods turn out to be broken: quantum computers allow encrypted Internet data transactions to become readable by anyone who happened to be listening. No more HTTPS, no more PGP. It sounds a little bit sci-fi, but that’s exactly the scenario that cryptographers interested in post-quantum crypto are working to save us from. And although the (potential) threat of quantum computing to cryptography is already well-known, this summer has seen a flurry of activity in the field, so we felt it was time for a recap.
How Bad Is It?
If you take the development of serious quantum computing power as a given, all of the encryption methods based on factoring primes or doing modular exponentials, most notably RSA, elliptic curve cryptography, and Diffie-Hellman are all in trouble. Specifically, Shor’s algorithm, when applied on a quantum computer, will render the previously difficult math problems that underlie these methods trivially easy almost irrespective of chosen key length. That covers most currently used public-key crypto and the key exchange that’s used in negotiating an SSL connection. That is (or will be) bad news as those are what’s used for nearly every important encrypted transaction that touches your daily life.