ATTEMPT ALL QUESTIONS AND PLS NO PLAGIARISM.

1. There are several different types of digital certificate.

(a) What is a code-signing certificate?

(b) What are the important fields of a code-signing certificate?

(c) Discuss the potential impact of management failures in the different phases of the lifecycle of a code-signing certificate.

2. Visit the website of a well-known commercial CA to establish:

(a) what levels of public-key certificate they issue;

(b) what credentials they require for registration for these different levels of public-key certificate;

(c) what liability they accept for these different levels of public-key certificate;

(d) how often they publish certificate revocation lists (CRLs); (e) how clients access CRLs;

(f) what advice they provide clients concerning the importance of checking CRLs.

3. The article Ten risks of PKI by Carl Ellison and Bruce Schneier [70] was written in 2000 and is widely available.

(a) Briefly summarise the ten risks described in the article.

(b) To what extent do you think these concerns remain valid today?