Chapter 10. Key Management


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Chapter 10. Key Management; Other Public-Key Cryptosystems

10.1 Key Management

Distribution of Public Keys

Distribution of Secret Keys Using Public-Key Cryptography

10.2 Diffie-Hellman Key Exchange

The Algorithm

Key Exchange Protocols

Man-in-the-Middle Attack

10.3 Elliptic Curve Arithmetic

Abelian Groups

Elliptic Curves over Real Numbers

Elliptic Curves over Zp

Elliptic Curves over GF(2m)

10.4 Elliptic Curve Cryptography

Analog of Diffie-Hellman Key Exchange

Elliptic Curve Encryption/Decryption

Security of Elliptic Curve Cryptography

10.5 Recommended Reading and Web Sites

10.6 Key Terms, Review Questions, and Problems

Key Terms

Review Questions

Problems



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No Singhalese, whether man or woman, would venture out of the house without a bunch of keys in his hand, for without such a talisman he would fear that some devil might take advantage of his weak state to slip into his body.

The Golden Bough, Sir James George Frazer

Key Points

  • Public-key encryption schemes are secure only if the authenticity of the public key is assured. A public-key certificate scheme provides the necessary security.

  • A simple public-key algorithm is Diffie-Hellman key exchange. This protocol enables two users to establish a secret key using a public-key scheme based on discrete logarithms. The protocol is secure only if the authenticity of the two participants can be established.

  • Elliptic curve arithmetic can be used to develop a variety of elliptic curve cryptography (ECC) schemes, including key exchange, encryption, and digital signature.

  • For purposes of ECC, elliptic curve arithmetic involves the use of an elliptic curve equation defined over a finite field. The coefficients and variables in the equation are elements of a finite field. Schemes using Zp and GF(2m) have been developed.


This chapter continues our overview of public-key encryption. We examine key distribution and management for public-key systems, including a discussion of Diffie-Hellman key exchange. Finally, we provide an introduction to elliptic curve cryptography.




Cryptography and Network Security Principles and Practices
Cryptography and Network Security (4th Edition)
ISBN: 0131873164
EAN: 2147483647
Year: 2005
Pages: 209

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