Crypto U1, Basic Principles

Crypto U1, Basic Principles

1. Vocabulary: Quizlet flashcards, password: imy002 URL: http://quizlet.com/15532068/everyday-cryptography-chapter-1-flash-cards/

   • Quizlet flashcards (http://quizlet.com/15532068/everyday-cryptography-chapter-1-flash-cards/) (tutor reviewed and approved) Password:  imy002 Vocabulary is used throughout the entire course.  This provides the formal definitions set in the first chapter.

2. 3 issues to consider when contemplating use of cryptography

   • cost
     • monetary
     • ease of use
     • efficiency of operation
   • strength
   • appropriateness of use

3. 3 different ways to maintain confidentiality of data

   • encryption
   • steganography
   • access control

4. attacks

   • 3 standard assumptions about attackers ability
     • has access to all ciphertexts
     • has some corresponding plaintext and ciphertext pairs
     • knows encryption algorithm
   • 2 types of crypto algorithm "breaks"
     • method to find key
       • for example: exhaustive key search
         • also known as a brute force attack
       • for example: use statistical properties of plaintext language to help reverse engineer key
     • weakness is found in algorithm and makes key unnecessary
   • How an attacker knows when he/she has found the correct key
     • apply key to known plaintext/ciphertext pairs
     • Has knowledge of plaintext language.
     • may have contextual information that gives a clue
   • kinds of attacks
     • exploiting short key length
     • dictionary attacks
     • exploiting key derivation process
     • time memory tradeoff attacks
     • cryptographic primitive-specific attacs
       • birthday attacks
       • statistical attacks
       • differential and linear cryptanalysis
     • algorithm specific attacks
     • side channel attacks
       • timing attack
       • power analysis
       • fault analysis
       • padding attacks
     • academic