The Code Book 50
The Code Book | |
author | Simon Singh |
pages | 401 |
publisher | Doubleday |
rating | 8/10 |
reviewer | Jon Katz |
ISBN | 0-385-49531-5 |
summary | The evolution of cryptography, from Mary Queen of Scots to the NSA |
Simon Singh has written a readable, comprehensible and significant book about cryptography.
"The Code Book: The Evolution of Secrecy From Mary, Queen of Scots, to Quantum Cryptography" (Doubleday, $US 24) chronicles the obsessive human interest in and importance of codes, from Elizabethan England to the intrigue-riddled halls of the NSA and the era of quantum cryptography.
Secrets and the codes that protect them are important. They've brought about the rise and fall of monarchs and won wars; in some techno-circles, cryptography is almost becoming a religion. Issues surrounding codes speak directly to the Net, computing, freedom, privacy and power. Singh, a British author, producer and physicist, wrote the best-selling "Fermat's Enigma," and directed a documentary on Fermat's Last Theorm that aired on PBS's "Nova" series.
From tales of buried treasure, to stories of how the legendary mathematician and code breaker Alan Turing secretly helped defeat the Nazis and how Navajos (called code walkers) used their language to fight the Japanese, Singh puts our contemporary fascination with cryptography into perspective. He writes crisply and logically, and an instinct for talking about cryptography in terms of its most interesting tales.
"For two thousand years, codemakers have fought to preserve secrets while codebreakers have tried their best to reveal them," he explains. "It has always been a neck-and-neck race,with codebreakers battling back when codemakers seemed to be in command, and codemakers inventing new and stronger forms of encryption when previous methods had been compromised."
This battle becomes increasingly more intense and relevant, as the free-wheeling structure of the Internet increasingly collides with the perceived interests of individual citizens, with privacy, and with the interests and operations of law enforcement officials and national security organizations.
Singh suggests that we are entering a golden age of cryptography. He quotes one cryptographer as saying: "It is now possible to make ciphers in modern cryptography that are really, really out of reach of all known forms of cryptanalysis. And I think it's going to stay that way." This view, writes Singh, is supported by one of the NSA's Deputy Directors, who told him: "If all the personal computers in the world - approximately 260 million computers - were to be put to work on a single PGP encrypted message, it would take on average an estimated 12 million times the age of the universe to break a single message."
"The Code Book" even ends with "The Cipher Challenge: 10 Steps to $15,000." Singh offers a code -breaking challenge in 10 separate stages. I'll pass, but some of you might want take a shot at it.
Cryptography is a complex, even arcane subject for laypeople and non techno-heads to read about it. To Singh's credit, he's written a book that cryptographers and newbies can love equally. "The Code Book" unlocks the sometimes impenetrable complexity that surrounds cyptography, an achievement all its own.
You can pick this book up at Amazon.
Re:One Time Pads and cypher technology (Score:1)
So there are some very difficult bits that have
to be delt with to make it work.
Re:One Time Pads and cypher technology (Score:1)
One time pads work by adding a number modulo 26 (or however many characters are in the alphabet used) and transmitting the result. For each character in the message (or bit etc.) you need one truly random character (or bit etc.). On the receive side the same set of random information and same process is used to decrypt the message.
Somehow two sites must be able to agree on a set of random information for the encryption/decryption process. The random information has to be truly random with no biases (i.e. flip a coin, heads are 1, tails are 0, not use some complex mathematical function. The flipper has to be honest, he has to faithfully report the stream of heads and tails. If he notices that a lot of heads have happened he can't influence the bit stream to be more evenly distributed) The transmit and receive side both have to destroy the pads as used. The mechanics of it make one time pads unwieldly for a lot of classes of information. You could theoretically for instance distribute N copies of the one time pad to N sites but then you increase the chance of intercepting the pads proportionally. As a result its better for point to point broadcasting as opposed to a multi-point broadcast.
As a result there is a lot of information still encrypted and transmitted by governments that isn't one time pad encrypted, much of which is useful to the NSA. The NSA doesn't just deal in encrypted material either, sometimes regional news or the lack thereof broadcasted is important information.
Re:One Time Pads and cypher technology (Score:1)
We can assume that in the not too distant future technology is able to fit enormous amounts of data in a small space.
Read this article [xerox.com] by Richard Feynman, where he states
I have estimated how many letters there are in the Encyclopaedia, and I have assumed that each of my 24 million books is as big as an Encyclopaedia volume, and have calculated, then, how many bits of information there are (10^15). For each bit I allow 100 atoms. And it turns out that all of the information that man has carefully accumulated in all the books in the world can be written in this form in a cube of material one two-hundredth of an inch wide--- which is the barest piece of dust that can be made out by the human eye. So there is plenty of room at the bottom! Don't tell me about microfilm!
Even if our technology does not come so far soon, it is obvious that we can expect small portable datastores with capacity good enough for creating usable One Time Pads.
Re:One Time Pads and cypher technology (Score:1)
I don't think so. Handing out an OTP of that kind (imagine something like a palm pilot) is as easy/complicated as handing out a metal key.
You also can't reuse a pad between two people you want to talk to
I was talking about an obscene amount of information stored in the OTP (comparable to the information of all books written). This could avoid the need for reuse.
Good Book! (Score:1)
I'd never really heard the details of Turing's later life. It's absolutely tragic that we lost such a genius at such a young age.
Re:One Time Pads and cypher technology (Score:1)
Lars
Lars
--
Some help on the Cipher Challenge (Score:1)
Anyhow, so of course I jumped in on the cipher challenge at the end of the book. The first two were easy, Stage 1 solved in minutes with vi and a quick series of %s/D/a/g type commands, and Stage 2 with a small perl script [danger-island.com].
I've coded up a quick and messy java app with a horrible interface to help out on Stage 3 (I think I need more help though, it might be in German. Luckily my girlfriend is Austrian). In the spirit of sharing with the /. community I've made the java app and the OCR-scanned-in cipher texts available on my web site [danger-island.com]. The applet link is not working yet, but you can download the source and compile yourself. It runs as an application too.
Finally, I also have set up a mailing list for anyone who wishes to discuss or collaborate on the cipher challenge. The subscribe info is on the web site [danger-island.com].
Re:Saw Singh Speak in Berkeley Recently... (Score:1)
Re:Good Book! (Score:1)
Another Problem with One Time Pads... (Score:1)
Is that they require both ends of the conversation to have known in advance they want secure communications.
Public key based systems, OTOH, allow two formerly unconnected parties to start a secure conversation from scratch. If they have somebody they both trust for identification, they can even be sure who they're talking to, but even without the latter they can at least have a private conversation.
Simon Singh & Horizon (Score:1)
Incidentally, I've always realised that all the Horizon and Equinox programmes were a joint effort between the UK/US/Australia/NZ but how much are they tailored for each country? We always seem to get a British voice-over but there often seems to be token British content in a predominantly US-centric programme
Oh, and where is "The Arts & Entertainment Network"?
Re:One Time Pads and cypher technology (Score:1)
OTPs have never been popular with military users. The level of traffic is too high and key distribution is a major problem. Today the problem is even worse. Not only are text messages being encrypted, but digitized voice and large quantities of computer/image data are traversing military networks.
OTPs are great if you have low volume, high security requirements and a reliable key distribution system such as a diplomatic pouch or trusted courier.
Machine (to include computers) ciphers are used for the vast majority of encrypted communications.
Re:Axis breaking Allied codes (Score:1)
The Brits had the Typex, a rotor machine that was similar to the Enigma.
The NSA has pictures of these machines on their web page [nsa.gov].
Interesting (Score:1)
*Yodify*
Re:Interesting (Score:1)
Simon Singh was on NPR too (Score:1)
Re:Simon Singh was on the connection (Score:1)
observations (Score:1)
1) It would seem that since there are two filters - and an "allowable/expected" error will occur with these filters - that retransmission will amplify these errors. I suppose the satelite itself could perform some authentication
2) The transmission method supposes two filters set to different "angles". If the sateliate is taking these packets in, then they *must* have the filters set to the proper angles as well. Is this not a very loud means of comprimizing this medium?
I apologize for the possible newbie-ness of these examples, I'm just curious. [translation, don't flame the snot out of me]
My
Quux26
Re:Navajo (Score:1)
My
Quux26
Re: One-time pad IS practically unbreakable.... (Score:1)
#include "disclaim.h"
"All the best people in life seem to like LINUX." - Steve Wozniak
Re:Singh's Fermat book (Score:1)
One Time Pads and cypher technology (Score:1)
(For those who don't know, a One Time Pad is an encryption system in which a given (private) key is used once then discarded, giving codebreakers no sample to analyse for patterns)
As far as I can tell, as long as the key is uncompromised, the OTP system is totally uncrackable. There is just nothing you can do against a key where each permutation is only applied once. Maybe this is why the NSA has been paying so much attention to private citizens, because it no longer has a chance to break government codes?
Or is there an approach to cracking the OTP system that hasn't been considered?
gnfnrf
Further explanation on the rare book cipher (Score:1)
Yes, the book method sounds like it's a one-time pad. One can suppose that the book contains enough circled letters to run the length of a plaintext. The part about the book being a rare one is merely a question of key management, as it ensures that only that copy of the book contains a key, and that copies of the book will be hard to come by.
However, I strongly doubt the key was used only once and then the book destroyed. I also have my doubts on the selection method used on the letters of the book. Whatever the method, this is certainly not even close to peudo-random series; the fact you're selecting letters from a given language means that some letters will be more likely to be selected than others. Some in-depth statistical or differential cryptanalysis on the ciphertext using some known plaintext attacks is likely to yield results very fast. Throw in a powerful computer and you're set to break what was once unbreakable.
But my point is: the above argument invokes techniques, knowledge and tools for the cryptanalysis that were not available to the 17th Century cryptanalyst. As a matter of fact, he could not conceive them in his wildest dreams.
With that in mind, it's hard to think that even quantum cryptography, which generates a keystream that seems random enough and prevents man in the middle attacks, will always remain secure.
"There is no surer way to ruin a good discussion than to contaminate it with the facts."
I'm reading it now (Score:1)
I'd recommend it.
Even better than "Fermat's Enigma"? (Score:1)
What i saw at amazon [amazon.com] and the excerpt from bookstore cool [bookstore-cool.com] made me real curious about this one.
Re:observations (Score:1)
One possible scenario is, to have an encrypted link to the satellite, decrypt there, encrypt anew and send the information elsewhere. This would mean that anyone using the satellite has to trust it's makers.
Ideally you want only the true recipient to decrypt the message, thus you have to pass the Photons without determining their polarisation. A simple mirror would do the job but that would (apart from the problem that the photons now have to travel through the atmosphere twice) only link a few points on the earth's surface and give no 'switching' capabilities.
The next problem is the path between your satellite uplink and the sender/recipient. Ideally the photon should travel from the sender to the recipient without it's polarisation being determined so it has to go from a satellite dish to optical fibre still without being measured.
If there are devices accomplishing this feat i'd really like to see them.
Other ways might employ interference between two photons and sending a 'translation' matrix to sender and recipient (so anyone may know the 'relation' between their photons, but only sender and recipient know the actual photons they sent), or devices sending two photons of unknown (but related) polarisation to two recipients (the measurement by one recipient would determine the state of the other photon).
Re:A quick observation regarding quantum encryptio (Score:1)
The problem of laser transmissions around the curvature of the earth was solved with satellites, though i would be interested about the design of switches that preserve the quantum nature of the transmitted bits, yet allow for routing.
It also essentially stated, that errors during transmission are to be expected but a constant monitoring of a middle man would result in an error rate of 25%, so as long as the transmission errors are in the percent range, a middleman can either be detected or can only glance at a very small percentage of the transmitted bits which shouldn't result in usable information for compressed data transmissions.
Another problem altogether would be a middleman attack, where the middleman can actively intervene in the link, posing as the recipient for the sender, decode, encode again thus posing as sender for the true recipient.
Since quantum transmission relies on multiple transmission paths (a one directional quantum path and two directional transmission of reference data) routing this data along physically distinct lines and maybe even changing the routing during transmission could prevent such attacks.
Re:One Time Pads and cypher technology (Score:1)
Re:Navajo (Score:1)
Re:On the Golden Age of cryptography... (Score:1)
Your neighbour won't find your old E-mails if they're PGP encrypted with IDEA because he probably doesn't have the tools or expertise necessary.
On the same note, PGP and other software are only available in their present states because people in the profession (of large number theory and cryptography) are bothering to remain paranoid and move forward faster than analysis of the previous codes.
Saw Singh Speak in Berkeley Recently... (Score:1)
One of the most interesting things that I caught was Singh's discussion of steganography--message hiding--and its tangential history. For all of us who've heard (or even claimed) that security through obscurity is no security, it's interesting to see that obscurity has quite a colorful history.
I was also impressed with Singh's handling of the social implications of limited-access strong cryptanalysis (ie. quantum computing or NSA-only factoring algorithm.) I got to ask him about this and he had an interesting perspective on the global financial/militaristic effect this might have.
Though I haven't had a chance to read any Singh, he's absolutely eloquent and certainly knowledgeable. I'd buy a copy if I could afford it (and I had the spare time to pick up any more books.)
Singh's Fermat book (Score:1)
One of my favourites was a brief proof which was an example of the faulty logic used by people to attempt to get the bounty for solving Fermat's riddle, which proves that 2=1....:
a = b
a*a = a*b
a(a) = ab
a(a) + a(a) = a(a) + ab
2a(a) = a(a) + ab
2a(a) - 2ab = a(a) + ab - 2ab
2a(a) - 2a(b) = a(a) - ab
2{a(a) - ab} = a(a) - ab
2 = 1
So now you know.....
Re:Another Problem with One Time Pads... (Score:1)
The advantage is that to start a secure channel with public key crypto, you need method to authenticate that the info you are getting is from who you think it's from, but it doesn't need to be free from eavesdroppers (e.g. I don't care if someone hears me reading my PGP key fingerprint over the telephone).
Code Book/Codebreakers? (Score:1)
Axis breaking Allied codes (Score:1)
Re:Errata? (Score:1)
hope that helps =D
(both books are awesome, and if you enjoyed them you may also like Between Silk and Cyanide: A codemaker's war)
Re:One Time Pads and cypher technology (Score:1)
Another problem with OTP's is creating a pad that is random enough. As you might know, using a randomizer function in a computer is almost never really random. Although it is possible to create fuly randomized values for a OTP (considering creating the key and distributing it), using OTP it is definitely more expensive than using public key's.
So for the latter, cracking a code from an OTP system depends on analysing one stolen OTP and trying to find the randomizer function that was used to create it.
Good read, but little mention of Magic / Purple (Score:2)
--
Navajo (Score:2)
Re:One Time Pads and cypher technology (Score:2)
You also can't reuse a pad between two people you want to talk to. (Unless you're only doing broadcasts.) Therefore, I have to arrange a secure line of communication (classically, a trusted courier) to send them a copy of the "I-them" pad, for every value of "them" with whom I want to exchange messages. I then have to mangage and keep secret all these different pads.
Increased storage density or faster processors won't help with these problems.
On the Golden Age of cryptography... (Score:2)
However, I find it hard to believe we have attained this age when crypto is almost on the threshold of total unbreakability. I think ciphers will always be broken, whether it is a simple Caesar cipher or quantum cryptography.
It is a bit like warfare: yes, it's becoming increasingly hard to break a cipher, but as ciphers become harder to analyse, so does the public become more knowledgeable on the subject.
In Ian Pears' novel 'An Instance of the Fingerpost', Cromwell's cryptographer uses a one-time pad whose key is a rare book, with some letters circled throughout the book. The key is the letters of the book. He then goes on to call the encryption scheme unbreakable. It was used by Kings and their spies to communicate safely.
Yet, we break such codes today without breaking a sweat. I am citing this example to show that, although our methods are being refined, so is the tools of cryptanalysis. In the end, I don't think we'll ever have a 100% perfect method of encryption and key management. Perfect cryptography will always require vigilance, intuition, deep thinking and a healthy dose of paranoia.
I'm not saying it's easy to break quantum cryptography (or, as it should be called, quantum key management.) I'm not saying it's not safe. I'm saying I doubt it'll be safe forever; it just seems safe now, as we haven't put a lot of energy into trying to break it yet.
"There is no surer way to ruin a good discussion than to contaminate it with the facts."
Errata? (Score:2)
Also, not really related, but I saw that "Nova" episode about Fermat's Last Theorem. All I can say about it was that it was incredibly fascinating, it was very well done to make clear what's obviously a very mathematical concept to someone without a lot of deep math background, and that hard-core mathematicians have absolutely no life whatsoever.
Next time your S.O. complains about you spending too much time in front of the keyboard, just get them to watch this show and see how those zany math-heads sit in their den/office doing not much more than doodling mathematic formulae on legal pads for as much as 18 hours a day, 7 days a week...
-=-=-=-=-
Re:Errata? (Score:2)
Which reminds me of a favourite joke:
The CompSci department had put in their latest request for a huge and expensive mainframe machine (this was the 1950s, remember). Exasperated, the university admin shouted "Why can't you be more like the Math department?! All they ever ask for is paper, pencils and wastebaskets! Or even better, the philosophy department -- they only ever ask for pencils and paper!
Sorry for wasting your time really
jsm
A quick observation regarding quantum encryption (Score:3)
While I accept that interception of a data stream is likely to cause modification to the underlying signal, so too should the natural chaos underlying any physical-realm transport. Any system even attempting to make quantum encryption a reality would have to be engineered to allow unplanned, non-predicted breaks in the link. Such expected breaks would be perfect opportunities for so-named "man in the middle" attacks, where the attacking agent would only need to compute expected replies.
It appears that the actual synthesis of the quantum-tuned keysystems is where the real "magic" goes on, and I agree, it's a seductive concept to have the literal photons in a stream be intrinsically keyed to their destination. But in order for such a system to be perfect, excessive order and stability(the same order and stability that would be presumed to be missing in case of an attack) is required.
In the meantime, the sheer inconvenience of this system still keeps pure mathematical cryptography in high demand. Even the best laser can not adjust for the curvature of the earth, and fiber isn't particuarly difficult to server *backhoe fade*. I can't really imagine quantum properties on radio signals, but then I'm not qualified to make that call. I do know back at Wireless '97, there were innumerable companies selling RF Fingerprinting technologies to combat cell phone cloning, but I'm rather sure the technology did not exploit quantum mechanics.
Yours Truly,
Dan Kaminsky
DoxPara Research
http://www.doxpara.com
Simon Singh was on theconnection (Score:3)
Fluffy, albeit with a hard centre 8/10 (Score:3)
The Code Book isn't *that* good - but then I doubt it ever could be. He gets a little muddled himself in places and there are better descriptions out there on the work of Bletchley Park (although he gives the Poles more of their due credit than most), but there are some gems in there too. His background writing, the side-tracking on Linear B, the revelations about how Diffie-Hellman-Merkle (and even RSA, to an extent) were beaten to their marks by us Brits but because that information was classified until very recently no-one knows it
He finishes with a look at the future and quantum machines - very topical and, a physicist by training, he seems more certain of his ground here - or maybe that's just because I know less about that than I did about the rest of the book.
He does a great job putting codes, ciphers and cryptography into context - both more the modern world and way back whenever.
If you're a cryptographer, this book will probably annoy more than inform, but I'm a sucker for pop science books and my knowledge of cryptography isn't so strong. I enjoyed it.