ENCRYPTION

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ENCRYPTION

• Jo Cromwell
• Cornelia Bradford

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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

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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
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Telegraph

• 1835-- Samuel Morse invented the Morse Code
• 1843-- Construction of experimental telegraph
  line from Washington to Baltimore (40 miles)

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Radio

• 1895 Changed Cryptology
• Communications were open for anyones inspection

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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

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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.
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Enigma Machine

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Enigma Machine
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Enigma Machine
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Encryption

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

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Decryption

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

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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

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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

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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

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Authentication

• Verifies that information comes from a trusted
  source
• Works hand-in-hand with Encryption to create
  Secure Environment

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How Do You Authenticate?

• Password
• Pass Cards
• Digital Signatures
• Biometrics
• Fingerprint Scan
• Retina Scan
• Face Scan
• Voice Identification

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JOYS

• End danger of information interception
• Keeps business information secure
• Even if Info/Password is intercepted
• Cant Read!

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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!

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References

• www.howstuffworks.com
• www.donet.com
• http//whatis.techtarget.com

• www.all.net/books
• www.cescomm.com