'Block ciphers' diaporamas de présentation

A Gentle Introduction to Cryptography

A Gentle Introduction to Cryptography Extended quote from Bruce Schneier's book, Secrets and Lies . Cryptography plays a role in computer security, but buggy computer systems and vulnerable communications are a reality that cryptography has not solved. Quote from Eugene Spafford

1.56k views • 120 slides

Applied Cryptography

Applied Cryptography. Autumn 2019. Lecture times. Regular lecture times: Thursdays 16:30-18:00 and 18:15-19:45 On the first week of September and after each two weeks thereafter (i.e. on the dates 05.09, 19.09, 03.10, 17.10, 31.10, 14.11, 28.11, 12.10(?) ) 413. aud.

1.07k views • 85 slides

Modern Block Ciphers

Modern Block Ciphers. CSE 651: Introduction to Network Security. Summary. Block Ciphers (Chapter 3) Feistel Cipher Structure (Chapter 3) DES: Data Encryption Standard (Ch. 3) 3DES (Ch 6.1) AES: Advanced Encryption Standard (Ch. 5.2). Monoalphabetic Substitution Cipher.

764 views • 52 slides

Special Purpose Hardware for Factoring: The Linear Algebra Part

Special Purpose Hardware for Factoring: The Linear Algebra Part. Eran Tromer and Adi Shamir Applied Math Dept The Weizmann Institute of Science SHARCS 2005. Cryptanalysis is Evil. A simple mathematical proof: The definition of throughput cost implies that cryptanalysis = time x money

605 views • 45 slides

Cryptography: from Theory to Practice (a personal perspective)

627 views • 45 slides

KATAN & KTANTAN A Family of Small and Efficient Hardware-Oriented Block Ciphers

559 views • 41 slides

Chapter 4

Chapter 4. Encryption. Objectives. In this chapter, you will: Learn the basics of encryption technology Recognize popular symmetric encryption algorithms Recognize popular asymmetric encryption algorithms Understand a variety of hash encryption algorithms

507 views • 36 slides

Classical Cryptosystems

Classical Cryptosystems. Shift Ciphers (Caesar) y= x+k (mod 26) Affine Ciphers y=ax+b (mod 26) Vigenere Ciphers codes=(02,14,03,04,18) Substitution Ciphers (26! Permutations) Sherlock Holmes P27 (Visual Substitution) The Playfair and ADFG[V]X Ciphers Block Ciphers

825 views • 32 slides

ECE454/CS594 Computer and Network Security

ECE454/CS594 Computer and Network Security. Dr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2011. Hashes and Message Digests. What hashes can do MD2 MD4, MD5, SHA-1 HMAC. Hash Functions.

458 views • 30 slides

Cryptography and Network Security Chapter 6

Cryptography and Network Security Chapter 6. Multiple Encryption & DES. clear a replacement for DES was needed theoretical attacks that can break it demonstrated exhaustive key search attacks AES is a new cipher alternative

638 views • 30 slides

Security: An Overview of Cryptographic Techniques

Security: An Overview of Cryptographic Techniques. With slides from: Debabrata Dash, Nick Feamster, Gregory Kesden, Vyas Sekar and others. Cryptography, Cryptographic Protocols and Key Distribution. Authentication Mutual Authentication Private/Symmetric Keys Public Keys Key Distribution.

721 views • 26 slides

Limiting Liability in a Federally Compliant File System

323 views • 26 slides

HASH Functions

HASH Functions. Hash Functions. condenses arbitrary message to fixed size h = H(M) usually assume hash function is public hash used to detect changes to message want a cryptographic hash function computationally infeasible to find data mapping to specific hash (one-way property)

647 views • 20 slides

New Directions In Cryptography

New Directions In Cryptography. Made Harta Dwijaksara , Yi Jae Park. Contents. Introduction Conventional Cryptography Public Key Cryptography One-Way Authentication Problem Interrelations Problem Trap Doors Computational Complexity Q&A. Introduction.

542 views • 20 slides

Stream Ciphers

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

561 views • 18 slides

Chapter 3

Chapter 3. Block Ciphers and the Data Encryption Standard. Stream Cipher. Block Cipher. Stream Cipher and Block Cipher. Table 3.1 Encryption and Decryption Tables for Substitution Cipher of Figure 3.2 . Feistel Cipher.

373 views • 17 slides

Block Cipher Modes

750 views • 17 slides

Mid-term Review

Mid-term Review. Network Security. Secure channel. SSL (and many others: incl. IPSEC) Shared key establishing Trusted party (Kerberos, etc. - to be covered) Public key methods. Diffie-Hellman. RSA N=pq; ed ? 1 (mod ?(N)) Public: e,N; Private: d,N Encrypt (m) : c ? m e mod N

323 views • 14 slides

What is a block cipher?

Online Cryptography Course Dan Boneh. Block ciphers. What is a block cipher?. Block ciphers: crypto work horse. n bits. n bits. E, D. PT Block. CT Block. Key. k bits. Canonical examples: 3DES: n= 64 bits, k = 168 bits

307 views • 12 slides

Modes of operation: many time key (CTR)

Online Cryptography Course Dan Boneh. Using block ciphers. Modes of operation: many time key (CTR). Example applications : 1. File systems: Same AES key used to encrypt many files. 2. IPsec : Same AES key used to encrypt many packets.

225 views • 7 slides