'Stream ciphers' diaporamas de présentation

Computer and Information Security

1.72k views • 139 slides

Symmetric-Key Encryption

Symmetric-Key Encryption. CSE 5351: Introduction to Cryptography Reading assignment: Chapter 2 Chapter 3 (sections 3.1-3.4) You may skip proofs, but are encouraged to read some of them. This course:. APPLICATIONS (security). Encryption Schemes. Crypto Protocols. Sign/MAC/hash

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Digital Signatures

Digital Signatures. Presented by Olga Shishenina. Outline. Cryptographic goals Message Authentication Codes (MACs) Digital signatures RSA digital signature Elliptic curve digital signature Comparison of ECDSA and RSA signature. Message authentication. Entity authentication.

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Encryption - I

Encryption - I. Definitions. Plaintext: easy to understand form (original message) Ciphertext: difficult to understand form Encryption: encoding (plaintext -> ciphertext) Decryption: decoding (ciphertext -> plaintext) Cryptology: study of encryption Cryptography: use of encryption

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Chapter 7

Chapter 7. Pseudorandom Number Generation and Stream Ciphers. Random Numbers. A number of network security algorithms and protocols based on cryptography make use of random binary numbers: Key distribution and reciprocal authentication schemes Session key generation

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Outline

Outline. Brief review Mainstream crypto-algorithms Symmetric encryption algorithms DES Asymmetric encryption algorithms RSA Merkle-Hellman Other crypto-related techniques Digital signature Digital certificate. Acknowledgements. Charles Pfleedger E. Spafford William A. Stein FOLDOC

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Block Cipher Modes of Operation and Stream Ciphers

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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.

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ECE454 / 599 Computer and Network Security

ECE454 / 599 Computer and Network Security. Dr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2012. Secret Key Cryptography. Modes of operation Stream cipher. Encrypting A Large Message.

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Chapter 20

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On Ciphers that Continuously Access the Non-Volatile Key

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Cryptanalysis on Clock Controlled Stream Ciphers

Cryptanalysis on Clock Controlled Stream Ciphers. Shinsaku Kiyomoto KDDI R&D Laboratories Inc. 2005.2.22. This is a joint work with Kyushu University (Prof. Kouichi Sakurai). Information about Myself. Shinsaku Kiyomoto (age 29) B.E. and M.E. from Tsukuba Univ. (1998 and 2000)

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Information Security

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One-Time Pad Or Vernam Cipher

One-Time Pad Or Vernam Cipher. Sayed Mahdi Mohammad Hasanzadeh Hasanzadeh@Raymandcrypto.ir Spring 2004. OTP System. The one-time pad, which is a provably secure cryptosystem, was developed by Gilbert Vernam in 1918.

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POLYMORPHIC CIPHERS

POLYMORPHIC CIPHERS. By: C.B. Roellgen Presented By: Prabal Kumar Gupta Id: 2005H103014. Contents. Introduction Design Goals Primitive Pseudo Random number Generators Operating Principle of PMC Design of primitive random number generators Security of PMC

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Security and Privacy over the Internet

Security and Privacy over the Internet. Chan Hing Wing, Anthony Mphil Yr. 1, CSE, CUHK Oct 19, 1998. Presentation Overview. Introduction Public-key cryptography: RSA Secret-key cryptography: DES The SSL protocol Open discussion. Introduction. Privacy

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Pseudorandom Generators

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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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Real-world Stream C iphers

Online Cryptography Course Dan Boneh. Stream ciphers. Real-world Stream C iphers. Old example (software) : RC4 (1987). 2048 bits. Used in HTTPS and WEP Weaknesses: Bias in initial output: Pr [ 2 nd byte = 0 ] = 2/256

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Cryptography

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