National Security and Cryptography Jude Vanover and Justin Gross

Overview WWII and the use of machine ciphers and its following mathematical encryption techniques WWII and the use of machine ciphers and its following mathematical encryption techniques Development of NSA Development of NSA Current issues in National Security Current issues in National Security Terrorist cryptography Terrorist cryptography Concluding Remarks Concluding Remarks

WWII Cryptography From the Allied Point of View cryptosystems were divided into two stages From the Allied Point of View cryptosystems were divided into two stages I. European (aka. German) II. Pacific (aka. Japan)  Each Stage Provided different challenges to national security  The beginning of modern day cryptosystems and National Security techniques

Pacific Stage for WWII Crypt.. Japan used many systems including Orange, Red, and Purple Machines. Japan used many systems including Orange, Red, and Purple Machines. These machines were complicated and difficult to crack These machines were complicated and difficult to crack All were eventually cracked by allied forces All were eventually cracked by allied forces Pearl Harbor was a result of inability to decipher Purple code at the time Pearl Harbor was a result of inability to decipher Purple code at the time After Pearl Harbor and the decipher of Purple, Japan switched to JN25 After Pearl Harbor and the decipher of Purple, Japan switched to JN25 Eventually JN25 was broken which aid greatly in the victory at Midway Eventually JN25 was broken which aid greatly in the victory at Midway

European Stage for WWII Cryptography Nazi Germany and its machine cipher the Enigma Nazi Germany and its machine cipher the Enigma The entire German Army, Navy, and Airforce based its communication on the device The entire German Army, Navy, and Airforce based its communication on the device

Technical Details on the Enigma I A complex Machine Cipher A complex Machine Cipher Revised many times to make it more secure Revised many times to make it more secure Based on the linguistic technique of transliteration in which each letter entered corresponded to a different letter of the of the alphabet when encoded Based on the linguistic technique of transliteration in which each letter entered corresponded to a different letter of the of the alphabet when encoded Easily solved by letter frequency, however…… Easily solved by letter frequency, however……

Technical Details on the Enigma II Changed the correspondence between each letter by means of a series of rotating gears called rotors Changed the correspondence between each letter by means of a series of rotating gears called rotors The Germans made the machine more complicated by adding more rotors, 5 by the wars end. The Germans made the machine more complicated by adding more rotors, 5 by the wars end. Looked a great deal like a typewriter Looked a great deal like a typewriter Allowed for Encryption and Decryption on the same machine settings because the final rotor in the series was reciprocal or reflective Allowed for Encryption and Decryption on the same machine settings because the final rotor in the series was reciprocal or reflective  Thus if E is the Encryption function then E(x) = cipher text, then E(cipher) = x…or E(E(x)) = x 26 contacts per side of each rotor and each key entered stepped the rightmost rotor to the left one step. For that rotor out, the stepping was exactly like a car odometer. 26 contacts per side of each rotor and each key entered stepped the rightmost rotor to the left one step. For that rotor out, the stepping was exactly like a car odometer. Each Day began with a specified starting position to the rotors Each Day began with a specified starting position to the rotors

3 Rotor Enigma Example

Other details on Enigma Theoretically impossible to crack with 150,000,000,000,000 starting states that move as messages are encoded and decoded Theoretically impossible to crack with 150,000,000,000,000 starting states that move as messages are encoded and decoded Problems arose because the starting positions were transmitted twice at the beginning of each repetition. This narrowed starting positions down. Problems arose because the starting positions were transmitted twice at the beginning of each repetition. This narrowed starting positions down. Eventually Enigma machines were obtained from U-Boats and other sources, analyzed, and cracked using Bombe. Eventually Enigma machines were obtained from U-Boats and other sources, analyzed, and cracked using Bombe. Bombe was a machine that iterated through the possible starting positions of the Enigma in order to find the correct position to decode. Bombe was a machine that iterated through the possible starting positions of the Enigma in order to find the correct position to decode.

WWII Cryptography Knowing information means saving lives, keeping information may cost lives. This is the core principle of National Security Knowing information means saving lives, keeping information may cost lives. This is the core principle of National Security Core principle of crytography Core principle of crytography Development of N.S.A. Development of N.S.A.

National Security Agency Coordinates, directs, and performs highly specialized activities to protect U.S. information systems and produce foreign intelligence Coordinates, directs, and performs highly specialized activities to protect U.S. information systems and produce foreign intelligence Signals Intelligence (SIGINT)- believed to have directly contributed to shortening WWII by one year Signals Intelligence (SIGINT)- believed to have directly contributed to shortening WWII by one year

National Security Agency Interest in cryptanalytic research led to first large-scale computer and first solid state computer Interest in cryptanalytic research led to first large-scale computer and first solid state computer Pioneered efforts in flexible storage which led to development of tape cassette Pioneered efforts in flexible storage which led to development of tape cassette Largest employer of mathematicians in the U.S. and perhaps the world Largest employer of mathematicians in the U.S. and perhaps the world

Current issues in National Security Unbreakable encryption may not be good for everyone Unbreakable encryption may not be good for everyone  Criminal Opportunists  Compromising national security or protecting individual freedoms?

Current issues in National Security British Solution to information monitoring British Solution to information monitoring The Clipper Chip and Key Escrow The Clipper Chip and Key Escrow

The Clipper Chip This is an public encryption technique using chips in communication devices This is an public encryption technique using chips in communication devices Uses the SKIPJACK algorithm Uses the SKIPJACK algorithm Proposed in 1993 by the US Govt Proposed in 1993 by the US Govt Basically a wire tap in all communication devices - telephones, computers, et.. Basically a wire tap in all communication devices - telephones, computers, et.. It allows the Govt to decode information at anytime time it deems necessary because they have all the keys (key escrow) It allows the Govt to decode information at anytime time it deems necessary because they have all the keys (key escrow) Provides a basis for the Govt to monitor criminal activities especially terrorism Provides a basis for the Govt to monitor criminal activities especially terrorism

Key Escrow: The Master Key EES – Escrowed Encryption System is a cryptosystem developed by the NSA that is certified secure and is willing to share with the public EES – Escrowed Encryption System is a cryptosystem developed by the NSA that is certified secure and is willing to share with the public Using things such as Clipper chip it gives the Govt access to all encoded information to prevent misuse Using things such as Clipper chip it gives the Govt access to all encoded information to prevent misuse Basically a huge library of everyone’s public and private keys Basically a huge library of everyone’s public and private keys Know as Public Key Infrastructure (PKI) or Certification Authority (CA) Know as Public Key Infrastructure (PKI) or Certification Authority (CA) Very large Privacy Issues Very large Privacy Issues

Current issues in National Security Laws and regulations protecting U.S. citizens Laws and regulations protecting U.S. citizens Bending the Rules Bending the Rules A “K” example A “K” example

Terrorist Cryptography Steganography- Hiding information in pictures Steganography- Hiding information in pictures Using encryption downloaded from the net, developed by people trying to protect civil liberties Using encryption downloaded from the net, developed by people trying to protect civil liberties

Steganography Steganography is the art and science of hiding the fact that communication is taking place Steganography is the art and science of hiding the fact that communication is taking place Digital files like photographs or music files can be slightly and still look or sound the same Digital files like photographs or music files can be slightly and still look or sound the same

Steganography How it works: How it works:  A picture is created by a series of dots  Inside each dot is a string of letters and numbers that computers read to create the image  A coded message or another image can be hidden in those letters and numbers

Steganography How to detect a hidden image or text in a picture How to detect a hidden image or text in a picture  Modification of redundant bits replace with message change the statistical properties of the cover medium  Statistical analysis may reveal hidden content, check to see if image deviates from the norm

Tough to Break Encrypted files found on Ramzi Yousef’s computer took over one year to decrypt Encrypted files found on Ramzi Yousef’s computer took over one year to decrypt

Concluding Remarks Keeping information secure is vital both in the private sector and the government sector Keeping information secure is vital both in the private sector and the government sector

Concluding Remarks Mixed Feelings on Clipper Chip and Key Escrow Mixed Feelings on Clipper Chip and Key Escrow  Makes encryption expensive for criminals  Makes encryption cheap and safe for private sector  Integrating “Big Brother” ?