PPT-Cryptography Lecture 3

Cryptography Lecture 3 So far Heuristic constructions construct break repeat Can we prove that some encryption scheme is secure First need to define what we mean by secure in the first place. 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 By . Abhijith. . Chandrashekar. . and . Dushyant. . Maheshwary. Introduction. What are Elliptic Curves?. Curve with standard form y. 2. = x. 3 . + ax + b a, b . ϵ ℝ. Characteristics of Elliptic Curve. 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.”. (Quantum Cryptography). The BIG Idea. Basic idea of cryptography – To keep information secure from prying eyes. . Current encryption is mathematically based. Basically there are several possible types of keys and if the sender and end user both know the key, they can exchange information securely. . Algorithms. Scott Chappell. What is Cryptography?. Definition: the art of writing or solving codes. Basic Encryption Methods. Caesar Shift. Simple Substitution Cipher. Fun to use, but are easily cracked by computers and even by humans. CS. . 111. Operating . Systems . Peter Reiher. . Outline. Basic concepts in computer security. Design principles for security. Important security tools for operating systems. Access control. Cryptography and operating systems. Josh Benaloh. Tolga Acar. Fall 2016. November 8, 2016. Practical Aspects of Modern Cryptography. 1. What is Money?. 106 billion people lived. 94% are dead. Most of the world’s wealth made after 1800. 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. to’s. . u. sing . OpenSSL. In this session, we will cover cryptography basics and explore cryptographic functions, performance and examples using . OpenSSL. . . July 2012. LAB: . http://processors.wiki.ti.com/index.php/Sitara_Linux_Training:_Cryptography. 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. Steven M. Bellovin. https://www.cs.columbia.edu/~smb. What is Cryptography?. Literally: “hidden writing”. (Technical, the entire field is “cryptology”, but almost no one except the NSA and historians uses that word.). 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 Benefits of Reading Books,Most people read to read and the benefits of reading are surplus. But what are the benefits of reading. Keep reading to find out how reading will help you and may even add years to your life!.The Benefits of Reading Books,What are the benefits of reading you ask? Down below we have listed some of the most common benefits and ones that you will definitely enjoy along with the new adventures provided by the novel you choose to read.,Exercise the Brain by Reading .When you read, your brain gets a workout. You have to remember the various characters, settings, plots and retain that information throughout the book. Your brain is doing a lot of work and you don’t even realize it. Which makes it the perfect exercise!