Brute Force: Cracking the Data Encryption Standard

In 1997 Matt Curtin along with a small team of like minded white-hat hackers set out to prove that the security encryption standard DES, (Data Encryption Standard) was no longer secure. For various reasons the US government had chosen not to allow an upgrade which would provide far superior protection. Curtin and the team known as DES-chell harnessed a vast array of computer buffs, and computers across America to prove this vulnerablity and show that this was a serious matter which needed urgent attention. This is Curtin's account of the process. What sets it apart from many other books on code, and computers is that it is highly accessible. This is a book about the process of discovering the code, but it is also a book about the ramifications, the politics, the arguments offered. It also offers, in highly accessible language background to the complex matters he talks about, which made it easy for me, a non-computer buff, to understand. His use of analogys were wonderful, so talking about the standard 56bit encryption likened it to having a tumbler safe, with only one tumbler with 10 numbers on it there are only 10 settings which could be the possible combination. The average chance of finding the correct setting will therefore take 5 turns. To increase the security you could either add an extra number to the combination, that is make the tumbler have 11 numbers, or by adding an extra tumbler you increase the number of combinations to 100 and automatically made the likelihood of finding the combination 10 times slower. He likens 56 bit security as having 56 tumblers. However the likelihood of finding the combination was still a possibility with that level of encryption. And this is what he set out to do, he and his team believing that the only standard should be 128 bits. He harnessed thousands of computers across america, and the way he did this is fully documented. What I really liked was another analogy he used here. He discussed the fact that the Brute Force search for the key involved a whole series of simple calculations, and Brute Force searches of the combination (that is searching every combination until you find one) is simply a matter of time. So the higher the bits used int he secutiry the exponentially longer time it takes. However using hugely intelligent computers isn't the best way to find it - it is like getting a trained mathmetician to do a series of 5th grade math sums. He might do them faster, but not that much faster. What you need is thousands of 5th graders working on the sums. So that's what they literally did. Using computers in homes and labs all over the US - although the key people refined the software in some interesting ways to increase the speed. This is the story of their search, the competition with other groups also searching for the key, and the eventual outcome of the search. The interesting part of the conclusion in the outcome of the search is that the Press really did not seem to understand the complex i

When approached by the author as to whether I was interested in reading Brute Force, I was-- with some reservations. It has been a while since I hung up my tech strategy hat to go work in the non-IT world. Also, even though I'm reasonably technical, I'm a long way from a Cypherpunk. I was a little concern that it would get too technical for me to really appreciate. To be honest, I was also curious whether there was enough material about DESCHALL to really warrant a full book. I had been aware of the crack when it happened, and had honestly not looked much further than the "brute force. took several months. ho hum." attitude that the press seemed to be applying to the story. I am pleased to say that I was wrong to be worried on both counts. First of all, Curtin is a blessedly clear writer. As he covers topics which are cryptography specific, he explains them. Furthermore, he explains them using simple language so that I had no problem understanding. You do not need to be a cryptographer to read this book. Second, there apparently is enough material for a full book. Curtin manages to set up a really interesting story that is fully placed in a political and social context. Bonus because he does that without rehashing ground that has been covered about PGP and Zimmerman in other books. I found myself really interested in the DESCHALL efforts. It was particularly interesting to start drawing the analogy with later distributed computing efforts that were essentially tested with this effort. The foreward by Gilmore was fun enough-- but then, I like his writing and I really like the EFF. I would recommend this book for someone interested in the history of computing, or for someone with a special interest in security issues. Some computer background helps, but you do not need to be a specialist to read and enjoy the book. Truthfully, the book is closer to 4 and a half stars than five-- but Curtin gets some extra credit for all the ways that he could have made it unreadable, but did not.

This is a complex book, touching on topics in technology, civil liberties, volunteerism and cooperation, and the profound gap between what lawmakers and computer programmers are able to enact. Considering how much this book says, Curtin has chosen a remarkably understated way of saying it. A true nerd, he presents with neither braggadocio nor modesty, certain that the final result is adequate to move the reader if the reader can be moved at all. Set the scene in the Clinton era, when the federal DES encryption standard was aging. It's origin was already under a cloud, because the NSA super-spooks had made last-minute and unexplained changes to some of its internals and slashed the key size that IBM had originally proposed. Loosely speaking, the key size is like the thickness of the encryption's armor - would you be truly at ease with anyone in the business of armor cracking, when they tell you that your armor didn't need to be nearly so strong? Then, the feds proposed a 'key escrow' scheme using the code-named Clipper chip. Roughly translated, this means "I'm from the government and I'm here to keep a copy of your deepest secrets safe for you." By the way - it's a federal crime to try to find out what the Clipper is doing, and it will self-destruct if you try to look inside. This is the world in which the super-spooks were saying "Trust the DES." The nerds were saying "like hell." A private security company, RSA, had posted a challenge and a cash reward. The cash was a few thousand dollars, a piddling amount that most people just wanted to shuffle off to a charity so they wouldn't have to deal with it. The real reward was bragging rights worth enormously more, and not just in money. The goal was to make the spooks and feds look like ninnies. The deep goal was to show that they were lying, and that world trade encrypted in DES was very likely an open book to the US spy agencies. The deeper goal was to create the world's largest supercomputer, with no budget. The deepest goal was to show that an informed citizenry still holds power over its government, even while playing at a crippling disadvantage. The nerds, of course, won. Curtin describes the challenges, the rivalries, the sabotage, and the victory. If your ear is tuned to his words, you'll hear the rising tension as the world's largest computer grows, month by month, to attack the world's largest computation. You'll see successive challenges compress the time scale from months down to a one-day time limit. You'll see the challenges met, and you'll see the notion of data security change before your eyes. I fault Curtin for only one tiny fact in the politics of this story. The legislators trying to ban strong encryption were waving the usual flags - "If we allow this, then the child pornographers and organized crime have already won." Guys, that battle was already lost. About 20 years earlier, Martin Gardner had published the details of the big-primes public-key code in the August 1977 Scie

Matt Curtin has written a fascinating book that courses through the history of cryptography, the power of social networks and the Internet to bring them into being, conquering a technological challenge through altruistic cooperation, the competitive spirit, the government's desire to intrude on its citizen's privacy and battle against government in behalf of individual freedom. It sounds like a lot and it is --- but Curtin is blessed with the ability to write in plain English, thus rendering even the most esoteric technology understandable. The central story revolves around DES, a 56-bit Data Encryption Standard, adopted by the U.S. government in the early 1980s. Proponents argued that DES was unbreakable because there were 76 quadrillion possible keys. Curtin does a masterful job of providing a brief, but thorough history of cryptography through the ages. He deserves an accolade for this. Cryptography is not simple subject and many writers on the subject presume the reader already knows cryptography. Curtin doesn't make this mistake. Throughout the 1980s and 1990s, technologists and civil libertarians became increasingly concerned that 56-bit DES wasn't secure enough; that it could be defeated and supposedly confidential data compromised. At the same time, the Clinton administration had banned the export of powerful encryption technology hurting businesses and was demanding that all producers of cryptographic systems provide the government with a key, literally a backdoor, so the government at its whim could access encrypted data. The Clinton White House, of course, claimed that law enforcement needed these powers to protect children from pornography, fight terrorism and the war on drugs. A commercial firm, RSA, announced cash prizes to the first entities to crack several encryption algorithms. Curtin and a few others resonded by organizing an effort to create a network where computer owners would devote unused CPU resources to an effort to crack DES. That is, they would apply up to 76 quadrillion keys to a message created by RSA in order to be the first to get it done. The story of this "brute force" effort is the bulk of Curtin's book and is compellingly interesting. It involves technology; the creation and evolution of software designed to test keys against the DES algorithm. Here again, Curtin makes what could be incomprehenisible esoterica clear and interesting to the lay reader. Although I've been involved with the technology for more than 40 years, I feel certain that even those who consider themselves "computer illiterate" would find Curtin's explanation of this effort understandable and interesting. Curtin's story within the story is how strangers with common interests were allowed to come together and pool their efforts via the Internet. Long before "social networking" became a catch phrase, the power of the Internet to facilitate social interaction and cooperation was demonstrated by efforts such as Curtin's, which

Brute Force: Cracking the Data Encryption Standard is the story of the life and death of DES (data encryption standard). In the early 1970s, the U.S. government put out an open call for a new, stronger encryption algorithm that would be made into a federal standard, known as FIPS (Federal Information Processing Standard.). Numerous solutions were submitted as the DES candidate, including one from IBM. The IBM solution, originally called Lucifer, was chosen to be used as the encryption algorithm. After that, it became known as DES. DES is the most widely used method of symmetric data encryption ever created. Its 56-bit key size means that there are roughly 72,000,000,000,000,000 (72 quadrillion) possible encryption keys for any given message. DES was always considered a strong encryption method, but strength is relative. The strength of an encryption system is measured by how resilient it is against attack. From the outset, it was known that DES was susceptible to brute force attacks. A brute force attack, also known as an exhaustive search is an attack against a cryptosystem in which all possible values for the key are attempted - the bigger the key, the more difficult the attack. It must be remembered that DES was developed long before desktop computers, so the feasibility of a computer that could perform a brute force attack against DES was rendered so expensive and infeasible that the 56-bit key space (in a 64-bit block) of DES was considered strong enough. In reality, Lucifer actually had an original design of a 128-bit block size and 112-bit key size, but politics got in the way, and DES was created in a crippled state from the onset. By 1997, DES was cracked, and the start of its downfall had commenced. Brute Force: Cracking the Data Encryption Standard is a firsthand account of how DES was broken. Author Matt Curtin was a member of the DESCHALL team, which was created in response to the RSA Security Inc. RSA Secret Key Challenge. The challenge was to break a DES-encrypted message. Brute Force comprises two interrelated parts. Part 1 is a short overview of cryptography and encryption. It also details how Curtin first became interested in cryptography in the Bexley, Ohio, public library. Part 1 sets the groundwork for the main subject matter of the book, which is Curtin's diary of how DES was broken via DESCHALL. The unofficial mantra of DESCHALL was that friends didn't let friends have idle computers. DESCHALL was led by Curtin, Rocke Verser, Matt Curtin, and Justin Dolske, and used an Internet-based distributed computing infrastructure. Since brute force attacks are naturally suited to distributed computing, it made for a perfect testing ground to break DES. Part 2 details the ups and downs of the project. Designing a software system to crunch up to 72 quadrillion is not a easy task, combined with key server crashes, competitive foreign groups, and the U.S. government on your back, made the travails of DESCHALL a challenging