{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Day1Fall06

# Day1Fall06 - An Introduction to Cryptology and Coding...

This preview shows pages 1–12. Sign up to view the full content.

An Introduction to Cryptology and Coding Theory Sarah Spence Adams Olin College [email protected] Gordon Prichett Babson College [email protected]

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Communication System Digital Source Digital Sink Source Encoding Source Decoding Encryption Decryption Error Control Encoding Error Control Decoding Modulation Channel Demodulation
Cryptology Cryptography Inventing cipher systems; protecting communications and storage Cryptanalysis Breaking cipher systems

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Cryptography
Cryptanalysis

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
What is used in Cryptology? Cryptography: Linear algebra, abstract algebra, number theory Cryptanalysis: Probability, statistics, combinatorics, computing
Caesar Cipher ABCDEFGHIJKLMNOPQRSTUVWXYZ Key = 3 DEFGHIJKLMNOPQRSTUVWXYZABC Example Plaintext: OLINCOLLEGE Encryption: Shift by KEY = 3 Ciphertext: ROLQFROOHJH Decryption: Shift backwards by KEY = 3

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Cryptanalysis of Caesar Try all 26 possible shifts Frequency analysis
Substitution Cipher Permute A-Z randomly: A B C D E F G H I J K L M N O P… becomes H Q A W I N F T E B X S F O P C… Substitute H for A, Q for B, etc. Example Plaintext: OLINCOLLEGE Key: PSEOAPSSIFI

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Cryptanalysis of Substitution Ciphers Try all 26! permutations – TOO MANY! Bigger than Avogadro's Number! Frequency analysis
One-Time Pads Map A, B, C, … Z to 0, 1, 2, …25 A B … M N T U 0 1 … 13 14 20 21 Plaintext: MATHISUSEFULANDFUN

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 32

Day1Fall06 - An Introduction to Cryptology and Coding...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online