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Week 3: Block Ciphers

Nov 15, 2013

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Where we've been. Classical techniques employ the same principles that underlie modern cryptosystems:substitutiontranspositionThese operations can be combinedGoal: enhance diffusion and confusion. Diffusion. Dissipate the statistical properties of the original plaintext so that you can't see the

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Week 3: Block Ciphers

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Block Ciphers and the Advanced Encryption Standard

2. Outline. 3.1 Introduction3.2 Substitution-Permutation Networks3.3 Linear cryptanalysis3.4 Differential cryptanalysis3.5 The Data Encryption Standard3.6 The Advanced Encryption Standard3.7 Modes of Operation. 3. 3.1 Introduction. A commonly used design for modern-day block ciphers is that of

936 views • 45 slides

THE FAMILY OF BLOCK CIPHERS “ SD-(n,k)”

THE FAMILY OF BLOCK CIPHERS “ SD-(n,k)”. S. Markovski D. Gligoroski V. Dimitrova A. Mileva. Outline. Introduction Block ciphers Quasigroups Encryption/Decryption Algorithms Conclusion Future work. Introduction. We present a new family of block ciphers “SD-(n,k)“.

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Categories of Ciphers

Categories of Ciphers. Substitution ciphers - replace letters in the plaintext with other letters or symbols, keeping the order in which the symbols fall the same. Transposition ciphers - keep all of the original letters intact, but mix up their order.

412 views • 14 slides

CIS 5371 Cryptography

CIS 5371 Cryptography. 5a. Pseudorandom Objects in Practice Block Ciphers B ased on: Jonathan Katz and Yehuda Lindell Introduction to Modern Cryptography. Block ciphers as encryption schemes or pseudorandom permutations.

330 views • 15 slides

The AES block cipher

Online Cryptography Course Dan Boneh. Block ciphers. The AES block cipher. The AES process. 1997: NIST publishes request for proposal 1998: 15 submissions. Five claimed attacks. 1999: NIST chooses 5 finalists

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CS363

Week 2 - Friday. CS363. Last time. What did we talk about last time? Substitution ciphers Vigenère ciphers One-time pad. Questions?. Project 1. Security Presentation. Michael Franzese. Secure Encryption Algorithms. How do you define good?.

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CS363

Week 2 - Wednesday. CS363. Last time. What did we talk about last time? Encryption Shift ciphers Transposition ciphers. Questions?. Security Presentation. Alexander Barrow. Substitution ciphers.

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Security Fundamentals (2) Encryption mechanisms

Security Fundamentals (2) Encryption mechanisms. 4/2011. 2-5 MODERN BLOCK CIPHERS. A symmetric-key modern block cipher encrypts an n-bit block of plaintext or decrypts an n-bit block of ciphertext . The encryption or decryption algorithm uses a k-bit key. . 2-5 Continued.

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Block Ciphers

Block Ciphers. Recall: Private-Key Encryption Algorithms. Also called single-key or symmetric key algorithms Both parties share the key needed to encrypt and decrypt messages, hence both parties are equal

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Classic Crypto

Classic Crypto. Overview. We briefly consider the following classic (pen and paper) ciphers Transposition ciphers Substitution ciphers One-time pad Codebook These were all chosen for a reason We see same principles in modern ciphers. Transposition Ciphers.

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Stream Ciphers

Stream Ciphers. CS 519 Cryptography and Network Security Instructor: Ali Aydin Selcuk. Stream Ciphers. Generate a pseudo-random key stream &amp; xor to the plaintext. Key: The seed of the PRNG

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Stream and Block Ciphers

Stream and Block Ciphers. Stream ciphers convert one symbol of plaintext immediately into one symbol of ciphertext Block ciphers work on a given sized chunk of data at a time. fsn. f. fs. fsnar. fsna. f. s. n. T. a. r. Stream Ciphers. Key. e. fsnarT. m. r. q. z.

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CIT 380: Securing Computer Systems

CIT 380: Securing Computer Systems. Classical Cryptography. Overview. Modular Arithmetic Review What is Cryptography? Transposition Ciphers Substition Ciphers Cæsar cipher Vigènere cipher Cryptanalysis: frequency analysis Block Ciphers DES. Modular Arithmetic. Congruence

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Modern Block Ciphers

Modern Block Ciphers. now look at modern block ciphers one of the most widely used types of cryptographic algorithms provide secrecy /authentication services focus on DES (Data Encryption Standard) to illustrate block cipher design principles. Block vs Stream Ciphers.

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Cryptography and Network Security Chapter 3

Cryptography and Network Security Chapter 3. Modern Block Ciphers. now look at modern block ciphers one of the most widely used types of cryptographic algorithms provide secrecy /authentication services focus on DES (Data Encryption Standard) to illustrate block cipher design principles.

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Cryptography

Cryptography. Lecture 3 Stefan Dziembowski www.dziembowski.net stefan@dziembowski.net. Plan. Encryption of multiple messages. Stream ciphers Block ciphers (an introduction) Some images in this document are take from From Wikipedia, the free encyclopedia. On the previous lecture:.

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Codes, Ciphers, and Cryptography-Ch 3.1

Codes, Ciphers, and Cryptography-Ch 3.1. Michael A. Karls Ball State University. Substitution and Permutation Ciphers. In Chapter 1 we looked at various examples of monoalphabetc substitution ciphers. A convenient way to describe these ciphers is via permutations !. Functions.

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Modern Block Ciphers and the Data Encryption Standard (DES)

Modern Block Ciphers and the Data Encryption Standard (DES). Again Special Thanks to Dr. Lawrie Brown at the Australian Defense Force Academy whose PowerPoint slides provided the basis for these slides. Recall: Private-Key Encryption Algorithms.

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Encryption Types &amp; Modes Chapter 9

Encryption Types &amp; Modes Chapter 9. Encryption Types Stream Ciphers Block Ciphers Encryption Modes ECB - Electronic Codebook CBC - Cipher Block Chaining CFB - Cipher Feedback OFB - Output Feedback. Stream Ciphers. One unit of the data stream is encrypted at a time.

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Fundamentals of Computer Security

Fundamentals of Computer Security. One-Time Pads Polygraphic Ciphers Transposition Ciphers. Ciphers. Public Key. Symmetric Key. Unkeyed. Classical. Stream. Block. Transposition. Substitution. One-time Pad. Monoalphabetic. Polyalphabetic. Nihilist. Vigenère. Autokey. Polygraphic.

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Secret Key Cryptography

Secret Key Cryptography. TE/CS 536 Network Security Spring 2006 – Lectures 6&amp;7. Block Encryption - 1. Stream ciphers are not suitable for long messages Block ciphers convert block to another: one-to-one reversible mapping Long enough to avoid known-plaintext attack

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Modern Block Ciphers

Modern Block Ciphers. will now look at modern block ciphers one of the most widely used types of cryptographic algorithms provide secrecy and/or authentication services in particular will introduce DES (Data Encryption Standard). Block vs Stream Ciphers.

809 views • 49 slides

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Week 3: Block Ciphers

Week 3: Block Ciphers

Presentation Transcript

Block Ciphers and the Advanced Encryption Standard

THE FAMILY OF BLOCK CIPHERS “ SD-(n,k)”

Categories of Ciphers

CIS 5371 Cryptography

The AES block cipher

CS363

CS363

Security Fundamentals (2) Encryption mechanisms

Block Ciphers

Classic Crypto

Stream Ciphers

Stream and Block Ciphers

CIT 380: Securing Computer Systems

Modern Block Ciphers

Cryptography and Network Security Chapter 3

Cryptography

Codes, Ciphers, and Cryptography-Ch 3.1

Modern Block Ciphers and the Data Encryption Standard (DES)

Encryption Types &amp;amp; Modes Chapter 9

Fundamentals of Computer Security

Secret Key Cryptography

Modern Block Ciphers

Encryption Types & Modes Chapter 9