PPT-Cryptography Lecture 19 Exponentiation

Compute a b ǁa b ǁ Ob ǁaǁ Just writing down the answer takes exponential time Instead look at modular exponentiation Ie c ompute a b mod N Size of the answer lt . However computational aspects of lattices were not investigated much until the early 1980s when they were successfully employed for breaking several proposed cryptosystems among many other applications It was not until the late 1990s that lattices w Intro to IT. . COSC1078 Introduction to Information Technology. . Lecture 22. Internet Security. James Harland. james.harland@rmit.edu.au. Lecture 20: Internet. Intro to IT. . Introduction to IT. CS 465. Last Updated. : . Aug 25, 2015. Outline. Provide a brief historical background of cryptography. Introduce definitions and high-level description of four cryptographic primitives we will learn about this semester. Sixth Edition. by William Stallings . Chapter 10. Other Public-Key Cryptosystems. “Amongst the tribes of Central Australia every man, woman, and child has a secret or sacred name which is bestowed by the older men upon him or her soon after birth, and which is known to none but the fully initiated members of the group. This secret name is never mentioned except upon the most solemn occasions; to utter it in the hearing of men of another group would be a most serious breach of tribal custom. When mentioned at all, the name is spoken only in a whisper, and not until the most elaborate precautions have been taken that it shall be heard by no one but members of the group. The native thinks that a stranger knowing his secret name would have special power to work him ill by means of magic.”. Josh Benaloh. Tolga Acar. Fall 2016. October 25, 2016. 2. The wiretap channel. Key (K. 1. ). Key (K. 2. ). Eavesdropper. Plaintext. (P). Noisy insecure. channel. Encrypt. Decrypt. Alice. Bob. Plaintext. Week two!. The Game. 8 groups of 2. 5 rounds. Math 1. Modern history. Math 2. Computer Programming. Analyzing and comparing Cryptosystems. 10 questions per round. Each question is worth 1 point. Math Round 1. CSE3002 – History of Computing. Group A: Daniel . Bownoth. , Michael Feldman, Dalton Miner, Ashley Sanders. Encryption. The process of securing information by transforming it into code.. Encrypted data must be deciphered, or . 1. Part I: Crypto. Part 1 . . Cryptography . 2. Crypto. Cryptology . . The art and science of making and breaking “secret codes”. What is cryptography?. Ceasar. Cipher. Public key cryptography. What is cryptography?. Cryptography.  or . cryptology.  (from . Greek.  . κρυπτός.  . kryptós. , "hidden, secret"; and . Richard J. Blech. Chief Executive Officer. Secure Channels, Inc.. Is there anyone here who cannot parse and explain this equation?. 2. If not, that’s ok.. 3. Why Pre-Computer Cryptography?. If you understand pre-computer crypto, you understand crypto!. 1. Administrative Note. Professor Blocki is traveling and will be back on Wednesday. . E-mail: . jblocki@purdue.edu. . Thanks to Professor Spafford for covering the first lecture!. 2. https://www.cs.purdue.edu/homes/jblocki/courses/555_Spring17/index.html. Josh Benaloh. Tolga Acar. Fall 2016. October 25, 2016. 2. The wiretap channel. Key (K. 1. ). Key (K. 2. ). Eavesdropper. Plaintext. (P). Noisy insecure. channel. Encrypt. Decrypt. Alice. Bob. Plaintext. Cyclic group G of order q with generator g.  G.  . G = {g. 0. , g. 1. , …, g. q-1. }. For any h .  G, define . log. g. h .  {0, …, q-1} as. . log. g. h = x  . The . art and science of concealing the messages to introduce secrecy in . information security . is recognized as cryptography. .. The word ‘cryptography’ was coined by combining two Greek words, ‘Krypto’ .