If not for world war and the quest to decode the enemies thoughts, we wouldn't have the luxury of computers way ahead of its time. The outcome was cryptography, a field that at the same time created two unmistakable branches: transposition and substitution. Enigma" নিয়ে। সে সময়কার রোমহর্ষক ইতিহাসের শ্বাসসরুদ্ধকর বর্ণনা আছে বইটিতে।সে ইতিহাস শীতল স্নায়ুযুদ্ধের,মর্মান্তিক ও একই সাথে চূড়ান্ত উত্তেজনাকর।ঐ সময়টাতেই Cryptography-র বিকাশটা হয় সবচে' বেশি। ততদিনে Cryptography-টা আর ভাষাবিদদের মধ্যে সীমাবদ্ধ নয়,বরং গণিতবিদ,দাবাড়ু,বিজ্ঞানীদের প্রাধান্যে এগিয়ে চলছে দ্রুতগতিতে।অপ্রতিরোধ্য "Enigma"কেও হার মানান Bletchley Park Ventris before long recognized dispatching center points like Knossos and Tylissos, giving himself the pieces of information he expected to disentangle the language. Scholastics were confused when Ventris reported that Linear B was in certainty an antiquated variant of the Greek language, and his revelation stood out forever as “The Everest of Greek Archeology.” Singh has created an authoritative, and engrossing read which both explains and humanises the subject… This intelligent, exciting book takes its drive from a simple premise – that nothing is as exciting as a secret.

Bazeries’ method of deciphering the Great Cipher of Louis XIV by analyzing by syllable frequency rather than letter. Legecy টা এখানেই, পরিসংখ্যান বিশ্লেষণের মাধ্যমে সেই টেক্সটও পাঠের পদ্ধতিও বের করলেন Code breaker-রা। প্রতিটা ভাষার ধ্বনিতত্ত্ব বিশ্লেষণ করলে দেখা যায়,এখানে সুনির্দিষ্ট কিছু ধ্বনি বেশি ব্যবহৃত হয়।যেমন ইংরেজিতে সবচে' বেশি ব্যবহৃত হয় "e",তারপর "a","t" ইত্যাদি।এভাবে বর্ণ বের করার পদ্ধতির নাম Frequency Analysis. আরবেরা এই পদ্ধতির জনক।ধর্মগ্রন্থে কোন কোন শব্দ কতোবার ব্যবহার In this way, message keys moved toward becoming fingerprints that uncovered the day key and Enigma settings.This outline will lead you through a portion of these pivotal occasions, straight up to the twentieth century, at the time codebreakers changed the course of World War II. You’ll get some answers concerning the expanding refinement of cryptography and become acquainted with how both cryptography and code-breaking are improved by data innovation. The Gold Bug এ এরকম পদ্ধতিতে গুপ্তধন বের করার কথা পড়েছিলাম,যদিও তখন কিছু বুঝিনি।ঐ অধ্যায়টা পড়ার পর পুরোনো প্রশ্নের উত্তর পেয়ে চমৎকৃত হয়েছি! The Times পত্রিকায় অক্সফোর্ডের এক ছাত্রের প্রেমিকাকে লেখা চিঠির পাঠোদ্ধার করেন,দেখেন সেখানে লেখা পালিয়ে বিয়ে করার কথা।পরের সংখ্যায় ঐ একই Encryption মেথড-এ তিনি বুঝিয়ে সুঝিয়ে লেখেন;দেখ বাবা,এভাবে পালিয়ে বিয়ে করাটাতো ঠিক না।���রের সংখ্যায় প্রেমিকা বেচারি সোজা-সাপ্টা ইংরেজিতে লিখে বসেন ,"Dear Charlie, write no more.Our cipher is discovered." ! A critical review of the book: " The Code Book: The Evolution of Secrecy from Mary, Queen of Scots to Quantum Cryptography, reviewed by Jim Reeds", Jim Reeds, Notices of the American Mathematical Society, vol.47, no.3, March 2000, pp.369–372. Retrieved 2009-02-19. (61KB PDF). As Neil Bohr said - "Anyone who can contemplate quantum mechanics without getting dizzy hasn’t understood it."

The methods used are described in detail, which is sometimes too advanced for beginners, and because of this, it´s sometimes advisable to skim the purely theoretical descriptions as in my case (laziness and layman). The military historical and political aspects are anyway much more interesting for the philistines of applied science.Be warned, though; reading this book will make you want to delve deeper into the subject matter. Fortunately, the author provides a further reading list at the end of the book, so there are plenty of future delights in store! Finally, thank you to everybody who took part in the Cipher Challenge and for making it such a success. It was a genuine pleasure meeting Cipher Challengers in various parts of the world, from Sydney to Milwaukee, and I only wish that I could have met more of you. If I do meet you, at least I will no longer have to be so tight-lipped. For a blabbermouth like me, the last two years have been a real struggle. Of Riddles Wrapped in Enigmas", Whitfield Diffie, The Times Higher Education Supplement, September 10, 1999, p.25. Retrieved 2009-02-19. Brings together…the geniuses who have secured communications, saved lives, and influenced the fate of nations. A pleasure to read."— Chicago Tribune Amazingly, Singh has the ability to make this rather complex topic understandable as well as entertaining. I am by no means mathematically inclined, but Singh explains the processes involved in each cipher he describes through baby steps and multiple analogies. If one doesn't work for you then the next will until you get it. This book actually makes you feel like you're learning something.

Charles Babbage, inventor of the modern calculator and computer, was the one who broke Vigeniere's polyalphabetic system, by using statistics to create an algorithm that helped reveal the keyword. The problem in the twentieth century has not been the development of undecipherable ciphers. The computer makes encoding very easy and quite unbreakable. But each ciphered message can only be deciphered using a key. The recipient has to know the key. Banks would hire messengers to deliver keys to encrypted messages that needed to be sent from one bank to another. That proved to be a bureaucratic nightmare, and as the Internet created a need for encrypted messages between individuals and online stores or other persons, the deliverer of the key became very important. Martin Hellman, Ralph Merkle, and Whitfield Diffie decided the problem was not insoluble. As Hellman said, “God rewards fools.”It would be hard to imagine a clearer or more fascinating presentation. . . . Mr. Singh gives cryptography not only its historical dimension but its human one."— The New York Times

The Code Book covers diverse historical topics including the Man in the Iron Mask, Arabic cryptography, Charles Babbage, the mechanisation of cryptography, the Enigma machine, and the decryption of Linear B and other ancient writing systems. [2] [3] Cryptography can basically be credited with the invention of computers. Furthermore, cryptographers are the reason you can send encrypted messages that nobody but the receiver can access, and the reason you can buy things over the Internet without people taking you credit card information. Thus, an alternate framework was important, and with the formation of the Enigma, cryptography ended up motorized. Ever since humans began writing, they have been communicating in code. This obsession with secrecy has had dramatic effects on the outcome of wars, monarchies and individual lives. Just a week later, my publishers received a fax from a team of Swedish researchers claiming that they had completed the entire Cipher Challenge. Two days later, on October 7, the formal claim arrived in the post. I called the spokesperson, Fredrik Almgren, and a somewhat cautious dialogue ensued. How did the Swedes know that this was really Simon Singh on the phone and not some impostor trying to steal their solution? I was the only other person in the world who also knew the plaintexts, and this became the decisive factor in establishing a relationship of trust.My only regret is that this great book has come far too late. If only someone had given it to me when I was 10, my secret plans for world playground domination might never have been foiled. Bah. Code maker-রা বর্ণ প্রতিস্থাপন এর পরিবর্তে Randomly বর্ণ নির্ধারণ করলেন এবারে।অর্থাৎ প্রেরক ইচ্ছেমতো বর্ণ ধরবেন,যার এক কপি থাকবে প্রাপকের কাছে।এবারে সহজে মেসেজ বের করার পদ্ধতি আর চলছেনা। A chronological series of cipher techniques; classic substitution, Caesar cipher, homophonic substitution, Vigenère cipher, book cipher, Playfair cipher, ADFGVX cipher, Enigma cipher, and two computer ciphers known as DES and RSA. Another reflection of the widespread interest was shown at a cryptography seminar in Oxford, where Cipher Challengers from Britain, America, Sweden, Switzerland and Norway arranged to meet up. Whenever I gave talks, both in Britain and abroad, I would meet Cipher Challengers from all walks of life and of all ages – from novices and schoolchildren to mathematicians and professional cryptographers. There was even a Fields Medallist who became involved. Vigenère’s cipher was first distributed in 1586 and called “Le Chiffre Indéchiffrable”, or the unbreakable cipher. It works this way: