National Security and Cryptography

Jude Vanover and Justin GrossJude Vanover and Justin Gross

Overview

WWII and the use of machine ciphers and WWII and the use of machine ciphers and its following mathematical encryption its following mathematical encryption techniquestechniques

Development of NSADevelopment of NSA Current issues in National SecurityCurrent issues in National Security Terrorist cryptographyTerrorist cryptography Concluding RemarksConcluding Remarks

WWII Cryptography

From the Allied Point of View cryptosystems From the Allied Point of View cryptosystems were divided into two stageswere divided into two stages

I. European (aka. German)I. European (aka. German)

II. Pacific (aka. Japan)II. Pacific (aka. Japan) Each Stage Provided different challenges to Each Stage Provided different challenges to

national securitynational security The beginning of modern day cryptosystems and The beginning of modern day cryptosystems and

National Security techniquesNational Security techniques

Pacific Stage for WWII Crypt..

Japan used many systems including Orange, Red, and Japan used many systems including Orange, Red, and Purple Machines.Purple Machines.

These machines were complicated and difficult to crackThese machines were complicated and difficult to crack All were eventually cracked by allied forcesAll were eventually cracked by allied forces Pearl Harbor was a result of inability to decipher Purple Pearl Harbor was a result of inability to decipher Purple

code at the timecode at the time After Pearl Harbor and the decipher of Purple, Japan After Pearl Harbor and the decipher of Purple, Japan

switched to JN25switched to JN25 Eventually JN25 was broken which aid greatly in the Eventually JN25 was broken which aid greatly in the

victory at Midwayvictory at Midway

European Stage for WWII Cryptography Nazi Germany and its Nazi Germany and its

machine cipher the machine cipher the EnigmaEnigma

The entire German The entire German Army, Navy, and Army, Navy, and Airforce based its Airforce based its communication on the communication on the devicedevice

Technical Details on the Enigma I

A complex Machine CipherA complex Machine Cipher Revised many times to make it more secureRevised many times to make it more secure Based on the linguistic technique of Based on the linguistic technique of transliterationtransliteration in which each in which each

letter entered corresponded to a different letter of the of the letter entered corresponded to a different letter of the of the alphabet when encodedalphabet when encoded

Easily solved by letter frequency, however……Easily solved by letter frequency, however……

Technical Details on the EnigmaII

Changed the correspondence between each letter by means of a series Changed the correspondence between each letter by means of a series of rotating gears called rotorsof rotating gears called rotors

The Germans made the machine more complicated by adding more The Germans made the machine more complicated by adding more rotorsrotors, 5 by the wars end. , 5 by the wars end.

Looked a great deal like a typewriterLooked a great deal like a typewriter Allowed for Encryption and Decryption on the same machine settings Allowed for Encryption and Decryption on the same machine settings

because the final rotor in the series was reciprocal or reflectivebecause the final rotor in the series was reciprocal or reflective Thus if E is the Encryption function then E(x) = cipher text, Thus if E is the Encryption function then E(x) = cipher text,

then E(cipher) = x…or E(E(x)) = xthen E(cipher) = x…or E(E(x)) = x 26 contacts per side of each rotor and each key entered stepped the 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 rightmost rotor to the left one step. For that rotor out, the stepping was exactly like a car odometer. exactly like a car odometer.

Each Day began with a specified starting position to the rotorsEach Day began with a specified starting position to the rotors

3 Rotor Enigma Example

Other details on Enigma

Theoretically impossible to crack with Theoretically impossible to crack with 150,000,000,000,000 starting states that move as messages 150,000,000,000,000 starting states that move as messages are encoded and decodedare encoded and decoded

Problems arose because the starting positions were Problems arose because the starting positions were transmitted twice at the beginning of each repetition. This transmitted twice at the beginning of each repetition. This narrowed starting positions down.narrowed starting positions down.

Eventually Enigma machines were obtained from U-Boats Eventually Enigma machines were obtained from U-Boats and other sources, analyzed, and cracked using and other sources, analyzed, and cracked using BombeBombe. .

Bombe Bombe was a machine that iterated through the possible was a machine that iterated through the possible starting positions of the Enigma in order to find the correct starting positions of the Enigma in order to find the correct position to decode.position to decode.

WWII Cryptography

Knowing information means saving lives, Knowing information means saving lives, keeping information may cost lives. This is keeping information may cost lives. This is the core principle of National Securitythe core principle of National Security

Core principle of crytographyCore principle of crytography Development of N.S.A.Development of N.S.A.

National Security Agency

Coordinates, directs, and performs highly Coordinates, directs, and performs highly specialized activities to protect U.S. specialized activities to protect U.S. information systems and produce foreign information systems and produce foreign intelligenceintelligence

Signals Intelligence (SIGINT)- believed to Signals Intelligence (SIGINT)- believed to have directly contributed to shortening have directly contributed to shortening WWII by one yearWWII by one year

National Security Agency

Interest in cryptanalytic research led to first Interest in cryptanalytic research led to first large-scale computer and first solid state large-scale computer and first solid state computercomputer

Pioneered efforts in flexible storage which Pioneered efforts in flexible storage which led to development of tape cassetteled to development of tape cassette

Largest employer of mathematicians in the Largest employer of mathematicians in the U.S. and perhaps the worldU.S. and perhaps the world

Current issues in National Security Unbreakable encryption may not be good Unbreakable encryption may not be good

for everyonefor everyone Criminal OpportunistsCriminal Opportunists Compromising national security or Compromising national security or

protecting individual freedoms?protecting individual freedoms?

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

The Clipper Chip

This is an public encryption technique using chips in communication This is an public encryption technique using chips in communication devicesdevices

Uses the SKIPJACK algorithmUses the SKIPJACK algorithm Proposed in 1993 by the US GovtProposed in 1993 by the US Govt Basically a wire tap in all communication devices - telephones, Basically a wire tap in all communication devices - telephones,

computers, et..computers, et.. It allows the Govt to decode information at anytime time it deems It allows the Govt to decode information at anytime time it deems

necessary because they have all the keys (key escrow)necessary because they have all the keys (key escrow) Provides a basis for the Govt to monitor criminal activities especially Provides a basis for the Govt to monitor criminal activities especially

terrorismterrorism

Key Escrow: The Master Key

EES – Escrowed Encryption System is a EES – Escrowed Encryption System is a cryptosystem developed by the NSA that is certified cryptosystem developed by the NSA that is certified secure and is willing to share with the publicsecure and is willing to share with the public

Using things such as Clipper chip it gives the Govt Using things such as Clipper chip it gives the Govt access to all encoded information to prevent misuseaccess to all encoded information to prevent misuse

Basically a huge library of everyone’s public and Basically a huge library of everyone’s public and private keysprivate keys

Know as Public Key Infrastructure (PKI) or Know as Public Key Infrastructure (PKI) or Certification Authority (CA)Certification Authority (CA)

Very large Privacy IssuesVery large Privacy Issues

Current issues in National Security Laws and regulations protecting U.S. Laws and regulations protecting U.S.

citizenscitizens Bending the RulesBending the Rules A “K” exampleA “K” example

Terrorist Cryptography

Steganography- Hiding information in Steganography- Hiding information in picturespictures

Using encryption downloaded from the net, Using encryption downloaded from the net, developed by people trying to protect civil developed by people trying to protect civil liberties liberties

Steganography

Steganography is the art and science of Steganography is the art and science of hiding the fact that communication is taking hiding the fact that communication is taking placeplace

Digital files like photographs or music files Digital files like photographs or music files can be slightly and still look or sound the can be slightly and still look or sound the samesame

Steganography

How it works:How it works: A picture is created by a series of dotsA picture is created by a series of dots Inside each dot is a string of letters and Inside each dot is a string of letters and

numbers that computers read to create the numbers that computers read to create the imageimage

A coded message or another image can A coded message or another image can be hidden in those letters and numbersbe hidden in those letters and numbers

Steganography

How to detect a hidden image or text in a How to detect a hidden image or text in a picturepicture Modification of redundant bits replace Modification of redundant bits replace

with message change the statistical with message change the statistical properties of the cover mediumproperties of the cover medium

Statistical analysis may reveal hidden Statistical analysis may reveal hidden content, check to see if image deviates content, check to see if image deviates from the normfrom the norm

Tough to Break

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

Concluding Remarks

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

Concluding Remarks

Mixed Feelings on Clipper Chip and Key Mixed Feelings on Clipper Chip and Key EscrowEscrow Makes encryption expensive for Makes encryption expensive for

criminalscriminals Makes encryption cheap and safe for Makes encryption cheap and safe for

private sectorprivate sector Integrating “Big Brother” ?Integrating “Big Brother” ?