Elliptic Curve Cryptography

Book review: Foundations of Security (Part 3 Introduction to Cryptography)

Adrian Citu

Chapter 12:  Symmetric Key Cryptography

The chapter starts with an introduction to cryptography that consists in explaining some notations and terminology. Then the block ciphers are explained and the following algorithms are introduced:

The second part of the chapter introduce the stream cyphers and as examples the One Time Pad and RC4.

Chapter 13: Asymmetric Key Cryptography

This chapter explains how the asymmetric key cryptography algorithms are working and briefly explains the RSA and Elliptic Curve Cryptography (ECC) algorithms; it also highlights one of the most important problem of the asymmetric key algorithms which is the public key creation and exchange.

Chapter 14: Key Management and Exchange

Key management refers to the process by which keys are generated, stored, agreed upon and revoked. The chapter is structured on 3 parts:

  • Key generation (how should new keys be created). For the key generation the authors focus on securely generating random numbers by using the C rand() function, using the Random APIs (CryptGenKey library or java.security API) or random device files.
  • Key Storage (how should keys be securely stored so that they cannot be easily stolen). The authors propose some solutions and starts from non secure storage “platforms” (as storing the keys into the compiled code or to a disk) until more secure “platforms” as external devices like smart cards, Hardware Security Modules (HSM).
  • Key agreement and exchange (how should to or more parties decide on a session key used to protect the confidentiality of their conversation). The authors present two ways that can be used to initiate a conversation:
    • generate a cryptographically random conversation key and  encrypt it with a public key
    • use Diffie-Hellman key exchange protocol

Chapter 15: MACs and Signature

This chapter presents Message Authentication Codes (MACs) and digital signatures. A MAC is  sequence of bits that can be attached to a message to verify where is originated and that is has not been tampered with. For MACs construction the authors present the following algorithms CBC-MAC and HMAC.

Chapter 16: Exercises for Part 3

As usually this chapter contains some questions and problems in order to test the comprehension of the notions discussed in the chapters 12-15.

(My) Conclusion

For me the book fulfill his goal: to present in a (rather) clear and concise way the fundamental notions about the security but what I disliked to this book is the writing style which I find it rather difficult to follow sometimes.