ENCRYPTION

Jo Cromwell

Cornelia Bradford

History of Encryption

Encryption has been around since antiquity

Cryptography began around 2,000 B.C in Egypt (Hieroglyphics)

The Spartans developed a transposition cipher

Greeks provided 1st recorded ciphers using numerical substitutions – 5th Century B.C.

Arabian 1st to document cryptanalytic methods - 1412

The Polybius Square

1 2 3 4 5

1 A B C D E

2 F G H I J

3 K L M N O

4 P Q R S T

5 U V W X Y/Z

Telegraph

1835-- Samuel Morse invented the Morse Code

1843-- Construction of experimental telegraph line from Washington to Baltimore (40 miles)

Radio

1895 – Changed Cryptology—

Communications were open for anyone’s inspection

Electromechanical Cryptography

The rotor – a thick disk with two faces, 26 brass contacts, plaintext input face,and output (ciphertext) face

Americans used rotors to break Japanese codes

Germany used similar machines to the rotor

Polish cryptanalysts broke Enigma early in WW2

First computers were used for decoding Enigma ciphers

The Enigma Machine

Like a typewriter, combining substitution and rotation ciphers in such a manner that the resulting overall cipher was difficult to break, unlike the constituent ciphers. The machine could decode as well as encoding messages.

The Enigma is configured by selecting several rotors from a larger set, placing them in a particular order and a particular start position. Received messages are decoded by setting the Enigma to the same state as the encoding Enigma X instead of and processing the message again. The result is clear text with the letter spaces.

Enigma Machine

Enigma Machine

Enigma Machine

Encryption

The conversion of data into ciphertext, that cannot be easily understood by unauthorized people.

Decryption

The process of converting encrypted data back into its original form so that it can be understood.

Computer Encryption

Text: Human, readable sequences of characters and words that are formed that can be encoded into computer readable format such as ASCII

Plaintext: What you have before encryption

Ciphertext: Encrypted test

Cipher: Usually refers to the method of encryption

Computer Encryption

ASCII: American Standard Code for Information Exchange

Most common format for text files in computers and on Internet

Unix & DOS-based systems use ASCII

Windows NT & 2000 use the newer Unicode

IBM uses an 8-bit code, EBCDIC

Computer Encryption

Symmetric Key Encryption

*Each computer has Secret Key

*Code provides key to decoding message

Public-key Encryption

*Combination of Private Key and

Public Key

*Pretty Good Policy

Authentication

Verifies that information comes from a trusted source

Works hand-in-hand with Encryption to create Secure Environment

How Do You Authenticate?

PasswordPass CardsDigital SignaturesBiometrics– Fingerprint Scan– Retina Scan– Face Scan– Voice Identification

JOYS

End danger of information interception

Keeps business information secure

Even if Info/Password is intercepted

– Can’t Read!

Government Standards

National Institute of Standards and Technology (NIST) adopted Advanced Encryption Standard (AES)

Banking industry will probably follow

One B-I-G Algorithm Party!

References

www.howstuffworks.com

www.donet.com

http://whatis.techtarget.com

www.all.net/books

www.cescomm.com