Reja Kirish II. Asosiy qism Jeferson kriptografik shifrlash qurilmasi. Uning ishlash prinspi Hagelin m-209 kriptografik shifrlash qurilmasi haqida umumiy tushunchalar. Enigma shifrlash qurilmasi. Shifrlash jarayonida bajaradigan algoritm

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4-rasm.Enigma kriptografik shifrlash qurilmasi ishlash prinspi

T harfini shifrlashni ko‘rib chiqamiz. 1)Klaviaturada T harfini bosganimizda algoritm quyidagicha bo‘ladi. T harfi K ga o‘zgaradi va g‘ildiraklardan o‘tishni boshlaydi. K harfi Statik g‘ildirakdan O‘ng g‘ildirakga o‘z holicha o‘tadi. K harfi o‘ng g‘ildirakda 10 birlik oldinga suriladi ya’ni U harfiga o‘tadi. U harfi o‘ng g‘ildirakda 5 birlik orqaga suriladi va P harfi hosil bo‘ladi. P harfi chap g‘ildirakda 8 birlik orqaga surilib H harfiga o‘zgaradi va Reflektor uni 4 birlik orqaga surib D harfiga o‘tkazadi. Qaytish jarayoni boshlanadi: Chap g‘ildirakda D harfi 3 birlik oldinga surilib G bo‘ladi. O‘rta g‘ildirak G harfini 11 birlik oldinga surib R hosil qiladi va R harfi o‘ng g‘ildirakda 5 birlik oldinga surilib W hosil qilinadi.W harfi Statik g‘ildirakda o‘zgarmasdan o‘tadi va jadvalga ko‘ra G harfiga aylanadi.Natijada T harfi shifrlanib G harfiga aylanadi.

1. 
   Wikipedia, Rotor machine
   Retrieved January 2014.
   
2. 
   Karl de Leeuw, The Dutch invention of the Rotor Machine, 1915-1923
   Cryptologia, January 2003, Volume XXVII, Number 1, pp. 73-94.
   
3. 
   Wikipedia, Enigma machine
   Retrieved January 2014.
   
4. 
   Dutch Patent NL10700
   7 October 1919. Transferred to Securitas on 5 May 1922. ¹
   

SIGABA kriptografik shifrlash qurilmasi haqida umumiy tushunchalar

SIGABA was a US cipher machine based on the electromechanical rotor principle. It was developed in the late 1930s as a joint effort of the US Army and Navy [1]. At the time it was considered a superior cryptomachine, intended to keep high-level communications absolutely secure. It was used throughout WWII and was so reliable that it was used well into the 1950s, when it was replaced by machines like the KL-7. As far as we know, SIGABA was never broken.

The image on the right shows one of the few SIGABA machines that have survived. It has the appearance of a rather bulky typewriter, featuring a full keyboard at the front. SIGABA is motor-driven and can print its text on a small strip of paper that runs across the front.

The machine has three banks of 5 wheels each, which is clearly visible in the patent below. The main bank (at the rear) contained 5 wheels with 26 contacts each. These were the main cipher wheels and worked similar to those of the German Enigma machine (more below).

The wheels were placed in a sub-assembly, sometimes called the rotor-basket, which could easily be removed from the machine by opening the top lid and releasing a few large bolts.

SIGABA CCM CSP-1700

Before, during and after WWII, the US Army and Navy each developed their own cryptographic systems. Neither service shared their knowledge with the other one, except for limited cooperation in the field of enemy signals intelligence. The first exception to this 'rule' was the development of SIGABA. It combined the knowledge of top cryptographers William F. Friedman and Frank B. Rowlett (Army) and Lieutenant Commander Laurence Safford (Navy).

The machine was called SIGABA by the US Army and ECM MARK II (Electric Cipher Machine) by the Navy. It is also known as Converter M-134 and CSP-888/889 (Navy). A modified Navy version is known as the CSP-2900. The Germans called it the American Big Machine. During and after WWII, a modified SIGABA, known as the Combined Cipher Machine (CCM) was used for Allied communication. The CCM is also known as ASAM 5, CSP-1600, CSP-1700 and SIGROD.

SIGABA was used extensively by the US Navy, from submarines to battleships [4], but also by the rest of the American armed forces. According to the NSA, over 5,000 machines were deployed by 1943, and well over 10,000 by the end of the war [15]. This is far less than the number of Enigma machines that were used by the Germans (more than 20,000), but still a significant quantity. Note however that the Germans used the Enigma for tactical messages, whilst the Americans mainly used the M-209 (Navy: CSP-1500) for that purpose. About 140,000 M-209 machines were made.

1. 
   NSA, Cryptologic Almanac 50th Anniversary Series, AFSAM-7
   Declassified by NSA on 12 June 2009.
   
2. 
   
   
3. 
   
   
4. 
   R Pekelney, ECM MARK 2 and CCM MARK 1
   Operating instructions for ECM Mark 2 (CSP 888/889) and CCM Mark 1 (CSP 1600).
   
5. 
   Timothy J. Mucklow, The SIGABA/ECM II Cipher Machine: A Beautiful Idea
   NSA, Center for Cryptologic History, 2015.
   

Xulosa

Qadimdan, kriptografik shifrlash qurilmalari muhim ahamiyatga ega hisoblanib kelgan. Ayniqsa urush davrlarida maxfiy ma‘lumot dushmanga ma‘lum bo‘lib qolmasligi uchun uni yashirish talab qilingan. Bu qurilmalar hozirgi zamon hujumlariga bardoshsiz hisoblansada, uning avlodlari hali hanuzgacha qo‘llanib kelinmoqda. Takidlash joizki, kriptografiya uzoq vaqt davomida davlat organlari aloqa tarmoqlarida almashinadigan ma'lumotlar muhofazasining ta’minlanishida qo‘llanib kelindi. Kompyuter tarmoqlari va elektron hujjat almashinuvi texnologiyalarining rivojlanishi moliya, bank ishlari, savdo-sotiq kabi sohalarda qo‘llanilishi axborot muhofazasining kriptografik usullarini umumjamiyat faoliyatining turli sohalariga keng kirib borishiga sabab bo‘ldi. Haqiqatan ham, aloqa tarmoqlarida axborotni muhofaza qilinishi, kriptografik usulda ta'minlash umumjamiyat taraqiyotining rivojlanish bosqichlari bilan bog‘liq bo‘lgan uzoq tarixiy manbalariga ega bo‘lib, umuminsoniyat jamiyatiga xizmat qilmasligi (ya'ni kriptografik usullarni keng omma tomonidan foydalanilishining cheklanishi) taajublanarli holat bo‘lar edi.

Foydalanilgan manbalar.

1. 
   David Kahn, The Codebreakers
   1967. pp. 192-195.
   
2. 
   Mavis Batey, Dilly, The Man Who Broke Enigmas
   2009. Hard cover, ISBN 978-1-906447-01-4.
   
3. 
   Frode Weierud, Personal correspondence
   August 2017.
   
4. 
   Dennis Richie, Dabbling in the Cryptographic World - A Story
   Updated 5 May 2000. Retrieved November 2011.
   
5. 
   Collection of M-209 patent and license agreements
   A66684. Declassified by NSA on 11 June 2014 (EO 13526). 
   
6. 
   Jean-Francois Bouchaudy, M-209 Cryptanalysis
   Retrieved July 2016.
   

Internet saytlar:

https://www.cryptomuseum.com/crypto/usa/jefferson/index.htm

https://www.cryptomuseum.com/crypto/enigma/hist.htm

https://www.cryptomuseum.com/crypto/hagelin/m209/index.htm