'Key stream' diaporamas de présentation

802.11 Network Security Architecture

802.11 Network Security Architecture. Security Fundamentals Encryption Protocols Robust Security. Main Idea. The main function of Wi-Fi is to act as a portal to access the network infrastructure .

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873 views • 71 slides

More on Cryptography CS 136 Computer Security Peter Reiher October 9, 2012

More on Cryptography CS 136 Computer Security Peter Reiher October 9, 2012. Outline. Desirable characteristics of ciphers Stream and block ciphers Cryptographic modes Uses of cryptography Symmetric and asymmetric cryptography Digital signatures. Desirable Characteristics of Ciphers.

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Classical Cryptography

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WLAN and IEEE 802.11 Security

WLAN and IEEE 802.11 Security. by, Atin Kumar Puja Thakral Soumya Das. Agenda. Intro to WLAN Security mechanisms in IEEE 802.11 Attacks on 802.11 Securing a wireless network Future Trends Summary. Why WLAN ?. The major motivation and benefit from wireless LANs is increased mobility.

737 views • 53 slides

Network Security

Network Security. Lecture 2 Secret Key Cryptography http://web.uettaxila.edu.pk/CMS/coeCCNbsSp09/index.asp. Waleed Ejaz waleed.ejaz@uettaxila.edu.pk. Overview. Cryptography Data Encryption Standard (DES) International Data Encryption Algorithm (IDEA) Advanced Encryption Standard (AES)

516 views • 39 slides

Modes of Operation

Modes of Operation. Topics. Overview of Modes of Operation EBC, CBC, CFB, OFB, CTR Notes and Remarks on each modes. Modes of Operation. Block ciphers encrypt fixed size blocks eg. DES encrypts 64-bit blocks, with 56-bit key

749 views • 38 slides

Cryptography, Attacks and Countermeasures Lecture 3 - Stream Ciphers

Cryptography, Attacks and Countermeasures Lecture 3 - Stream Ciphers. John A Clark and Susan Stepney Dept. of Computer Science University of York, UK {jac,susan}@cs.york.ac.uk. Stream Ciphers. Part I: Pseudo-random number generators. Lots of Bad Ways Part II: Divide and conquer attacks.

548 views • 36 slides

Stream Cipher

547 views • 32 slides

Stream Cipher

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More on Cryptography CS 236 On-Line MS Program Networks and Systems Security Peter Reiher

More on Cryptography CS 236 On-Line MS Program Networks and Systems Security Peter Reiher. Outline. Desirable characteristics of ciphers Stream and block ciphers Cryptographic modes Uses of cryptography Symmetric and asymmetric cryptography Digital signatures.

393 views • 29 slides

MD5 Cracking

592 views • 26 slides

Cryptographic Foibles

Cryptographic Foibles. COEN 225 Secure Coding. False Assumptions. Fresh from the press: RAM retains memory after shutdown Retention boosted by cold air Allows access to encryption keys after system shutdown.

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Fundamentals of Computer Security

Fundamentals of Computer Security. More Classical Ciphers. Attacks on Cryptosystems. Ciphertext Only Attack Chosen-Plaintext Attack Known-Plaintext Attack Rubber-hose Attack. Cryptanalysis.

459 views • 24 slides

Padding Oracle Attacks

Padding Oracle Attacks. Satish B Securitylearn.wordpress@gmail.com. 20/08/2011. Cryptography Attack. Agenda. Cryptography Basics Padding oracle attack Exploitation Padding oracle in .NET Tools Remedy. Cryptography Basics.

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A Short Introduction to Stream 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 & xor to the plaintext. Key: The seed of the PRNG

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Stream Ciphers

Stream Ciphers. Making the one-time pad practical. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. ?. Binary One-Time Pad. Idea behind stream ciphers. Start with a fixed-length, shared secret. This is generally called the seed s.

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Bishop: Chapter 11 An Overview of Cipher Techniques (in the context of networks) (11.1-11.3)

Bishop: Chapter 11 An Overview of Cipher Techniques (in the context of networks) (11.1-11.3). Topics. Problems with Design of Ciphers Stream and Block Ciphers A Brief Overview of Network Security ? more in Chapter 26 Privacy-enhanced E-Mails (PEM) Advanced Topics: SSL, IPsec

217 views • 12 slides

Encrypting with Block Ciphers

Encrypting with Block Ciphers. CS 470 Introduction to Applied Cryptography Instructor: Ali Aydin Selcuk. How to Encrypt with a Block Cipher?. Electronic Codebook (ECB) Mode: The naive way.

232 views • 9 slides