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Venona

LB

Lauren Blachorsky

Transcript

Lauren Blachorsky

Aislinn Deely

Nicola Kornbluth

Rui Yan Ma

Shayna Sosnowik

VENONA

DECLASSIFIED

What effect does reusing keys have?

(P + K)

(P + K)

-

__________

P-P

Decrypting One Time Pads

Because the keys "cancel out" we can now study this based on the rules of language.

Claude Shannon

  • If you have the key, decryption is easy. Just subtract the key from the cipher text.
  • If you don't have the key, the encryption is unbreakable.
  • Claude Shannon, the "Father of Information Theory" set up a framework for perfect secrecy in a key
  • If you use a key with perfect secrecy, your encryption will be unbreakable

One Time Pad

  • Feb 1, 1943: Venona Begins
  • May 1945: Soviet Codebooks Found
  • July to Dec 1946: messages translated, including one about the atomic bomb
  • 1948 to 1951: Venona exposes major KGB espionage agents
  • 1953: Rosenbergs executed
  • October 1, 1980: Venona ends
  • 1995: Venona begins process of declassifying documents

So How Did Venona Do It?

  • A one time pad is a type of encryption
  • The key is a string of randomly generated, non reusable digits
  • One Time Pads were the form of encryption used by the Soviets during WW II and the Cold War

The Soviets messed up.

They re-used the one time pad books. This allowed Venona to study frequencies of messages.

1. Choose a message you would like to encrypt.

Meet At Macaulay

Encryption

2. Represent the message in numbers using a code book.

Meet = 7934 At = 2157

Macaulay = 1139

  • The process of relaying information so that undesired third parties can not read it
  • Plain-text is encrypted with a key, into cipher-text
  • There are many real life applications to encryption
  • The intended recipient is able read the cipher-text using a decryption key

3. Break the numbers of your encoded plain text into groups of five digits. Line this up with the key.

79342 15711 39000

13962 70992 65172

encoded plain text

key

4.Add the groups of your message to the one time pad, one digit at a time. This should be done by adding (mod 10).

plain text

7 9 3 4 2 1 5 7 1 1 3 9 0 0 0

key

+

1 3 9 6 2 7 0 9 9 2 6 5 1 7 2

________________________________

cipher text

8 2 2 0 4 8 5 6 0 3 9 4 1 7 2

Using a One Time Pad,

MEET AT MACAULAY

has become

82204 85603 94172

References

The Venona Project

  • Setting: World War II
  • Purpose: Decrypting Soviet communication lines
  • A top secret small group in the NSA began to work on this project in 1943, eventually called the VENONA project
  • This project continued into the Cold War

Benson, Robert L. The Venona Story. Fort George G. Meade: Center for Cryptologic History, n.d. Print.

Haynes, John Earl., and Harvey Klehr. Venona: Decoding Soviet Espionage in America. New Haven, CT: Yale UP, 1999. Print.

Ramnum, Marcus. "One-Time-Pad (Vernam's Cipher) Frequently Asked Questions."One Time Pad Vernam Cipher FAQ. Marcus Ramnum, 1 Jan. 1995. Web. 28 Nov. 2012. <http://www.ranum.com/security/computer_security/papers/otp-faq/>

"Secrets, Lies, and Atomics Spies." Secrets, Lies, and Atomics Spies. WGBH, Boston, Massachusetts, 18 June 2003. Television. (The youtube video- MLA Format)

Trappe, Wade, and Lawrence C. Washington. Introduction to Cryptography: With Coding Theory. Upper Saddle River, NJ: Pearson Prentice Hall, 2006. Print.

Tyson, Peter. "Read Venona Intercepts." PBS. PBS, 1 Jan. 2002. Web. 28 Nov. 2012. <http://www.pbs.org/wgbh/nova/venona/intercepts.html>.