By Cindy Flores, Hyeok Jung Kim, Dalia Moradi, Abanob Saleh, Xi Ye You Seminar 3: Science & Technology of NYC, Professor Kent D. Boklan

Introduction Significance How It Works

On February 1, 1943, a small group of code breakers of the U.S. Army’s Importance of the Venona Project The Code (Vernam Cipher) and How it Works Signal Intelligence Service (SIS) launched the VENONA Project, a secret • Exposed the Soviet spy ring and information about the atomic bomb • Proven to be mathematically secure under ideal implementation by counterintelligence program to decrypt and exploit communication by the • Lasted from 1943 to 1980, declassified in 1995- from World War 2 Claude Shannon Soviet Union. throughout the Cold War (1947-1991) 1) Represent plain text into numbers (alphabet positioning.. ie: A=1) • Exposed Julius and Ethel Rosenberg for espionage and conspiracy to 2) Create a randomly generated key that is the same length as the plain Background provide atomic secrets to the USSR. As a result, they were executed text by electric chair in 1953. 3) Combine the plaintext and random key using XOR or modular addition History • They were implicated by their in-laws Ruth and David Greenglass, 4) Convert the numbers back into cipher text • The code breakers were named “Arlington Hall” after their communists who were also Soviet spies 5) To get back to the plain text, XOR the key again or subtract using headquarters in Virginia • Alger Hiss was a former U.S. State Department official who was modular arithmetic to get the ciphertext. • “Venona” was the code word for the project convicted of perjury in 1950 for involvement in a communist • The SIS led to creation of the National Security Agency (NSA) espionage ring. During this time, many Americans had a fear of domestic communism (The “Red Scare”). Plaintext Initial Discoveries • There were 5 code systems used by the Soviet Union - Trade representatives (the Soviet Gov’t Purchasing Commission) - Diplomats (used by members of diplomatic corps) Key - KGB (Soviet Espionage Agency) - GRU (the Soviet Army General Staff Intelligence Directorate) - GRU – Naval (Soviet Naval Intelligence Staff)

Information Theory Ciphertext

• Claude Shannon, the Father of Information Theory, says that the key

used in encryption must be random for it to be secure

• Encryption: to encode messages or information so that only intended The VENONA Breakthrough recipients can read it and unauthorized parties cannot. • Use a key to encrypt the message (plaintext) into the ciphertext Who broke it and how? • Recipient uses a key to decrypt the ciphertext. • Richard Hallock noticed that the Soviets were reusing some of their • XOR (⊕): Addition of numbers (mod 2) keys • x(Mod n):The remainder, when x is divided by n • Since keys have to be random and only used once, it was inefficient Effectiveness • Binary: Base 2 number system (1,0) for the Soviets to create new ones. So, they reused the keys. • The ciphertext does not give any information about the plain text • When the Soviets used XOR in the Vernam cipher, the repetition of except for the maximum length of the message.

the key meant that the plaintext could be found by XORing two cipher The randomness of the key means that even if a computer could try November 1943 - May 1945: military • team finds Soviet texts together. February 1, 1943 – Lieutenant Richard out every possible key, more than one plausible plaintext could be Hallock first breaks codebooks in Saxony • Physical copies of the keys were often carried around and weren’t Venona project begins yielded. Soviet diplomatic and Schleswig, properly disposed of after use cipher Germany

Drawbacks Key Figures • Keys have to be randomly generated each time a message is sent. • Gene Gabreel • Since this is a mechanical code, there is no way to verify July – December - Was a new member of the army intelligence group when she was 1953 – Rosenbergs 1948 – 1951 – the 1946 – Meredith authentication. executed for Venona project Gardner translates recruited and assigned to start the VENONA project conspiracy to commit exposes major KGB messages including • Lieutenant Richard Hallock espionage espionage agents one about the atomic bomb - Discovered the repetitions and pattern in other Soviet codes, References leading to the first partial decryption in 1943 Carter Clarke, Robert, Lamphere, Gene Grabeel, Meredith Gardner, Cecil, and Phillips, Kim Philby, Klaus Fuchs, Elizabeth Bentley,. "The Venona • Cecil Phillips Story." (n.d.): n. pag. NSA.gov. Web. 24 Nov. 2014.

- Cryptographer who first discovered the mathematical pattern in Klher, Harvey. "Venona." Google Books. Yale University, 1999. Web. 24 Nov. 2014.

1995 – Venona the Soviet cryptosystem and break the KGB cipher Linder, Douglas. "The Alger Hiss Trial." The Alger Hiss Trial. N.p., 2003. Web. 24 Nov. 2014. October 1, 1980 – documents begin to Venona project ends • Meredith Gardner Linder, Douglas. "The Trial of Ethel and Julius Rosenberg." The Trial of Ethel and Julius Rosenberg. N.p., 2008. Web. 23 Nov. 2014. get declassified - Made key code breaks and worked with the FBI to discover many NSA. "Declassification and Transparency- Venona." Venona. NSA, 15 Jan. 2009. Web. 24 Nov. 2014.

espionage agents "Venona: Soviet Espionage and The American Response 1939-1957."Central Intelligence Agency. Central Intelligence Agency, 19 June 2013. Web. 24 Nov. 2014.