tailieunhanh - the internet encyclopedia volume phần 4

Nhiệt độ bên trong thiết bị có thể được cao hơn đáng kể hơn so với không khí trong phòng. Mặc dù mật độ ngày càng tăng đã mang lại giảm dòng ở cấp mạch tích hợp, tản nhiệt vẫn là một mối quan tâm lớn. Nếu một hệ thống làm mát thất bại, lỗ thông hơi bị chặn, | Secure Sockets Layer SSL Robert J. Boncella Washburn University E-commerce and Secure Communication Certification Authorities 266 Channels 261 SSL Architecture 266 Overview 261 Overview 266 Definition of E-commerce 261 Connection Process 267 Secure Channels 262 Record Protocol 267 History of Secure Channels SSLvl to v3 PCT TLS Transport Layer Security 268 TLS STLP and WTLS 262 SSL and TLS Protocols Details 268 Internetworking Concepts Necessary for Cipher Suites and Master Secrets 270 E-commerce 262 Status of SSL 270 Clients and Servers 262 SSLv3 and TLS and Commercial Use 270 Communication Paths 262 Advantages and Disadvantages of and The OSI Model and TCP IP 263 Alternatives to SSL TLS 271 Cryptographic Concepts used in SSL and TLS 266 Glossary 272 Encryption 266 Cross References 272 Key Sharing 266 References 272 Digital Signatures 266 Further Reading 273 Message Digest Algorithms 266 E-COMMERCE AND SECURE COMMUNICATION CHANNELS Overview This chapter provides an overview of how the SSL protocol and its variant the TLS protocol are used to establish and operate a secure communication channel. It is assumed that the readers of this chapter are nontechnical in their academic background. As a result some space will be spent in explaining the background concepts necessary for a full understanding of SSL and TLS. If the reader requires more technical detail Boncella 2000 is suggested. This chapter has five major sections. First is a discussion of the need for and history of secure channels for e-commerce. Second is an overview of the internetworking concepts necessary to appreciate the details of SSL and TLS protocols. Third is a brief review of cryptographic concepts used in SSL and TLS. Fourth is a detailed exposition of SSL and TLS. And finally is a discussion of SSL and TLS protocol s status in e-commerce its strengths and weakness and possible alternatives. Definition of E-commerce E-commerce may be defined as the use of electronic or optical transmission .