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