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,
Plaintext: What you
readable sequences of
characters and words
that are formed that
can be encoded into
computer readable
format such as ASCII
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
Public-key Encryption
*Combination of
Private Key and
Secret Key
Public Key
*Code provides key to
decoding message
*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?
Password
Pass Cards
Digital Signatures
Biometrics
–
–
–
–
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.all.net/books
www.donet.com
www.cescomm.com
http://whatis.techtarget.com