Transcript ppt
Final Exam Review • Exam time is Aug. 2nd 2:00pm – 3:50pm in the same classroom. • All semester’s content will be tested, but more on content after midterm exam #2. • What actually covered in the final exam: – All questions in the 4 homework assignments. – Questions/examples in previous two midterm review slides – Questions/examples in this review slides. • You need to compute out the final numerical results in your answer. Do not simply write down the formula as your answer. – You can bring a calculator (no computer, iPhone, etc) – The numbers in exam are easy to comput Question Types – Knowledge questions – True or false statement • If false, explain why and give the correct statement – Protocols – Calculations Knowledge Question Examples • What are the two classes of cryptography? • Which one is similar to shuffling poker card: Substitution cipher or transposition cipher? • DES has fixed-size key while AES has options to choose several different sizes of key. Why currently people use 3DES instead of DES? • What are the pros and cons for symmetric key crypto? Public key crypto? – Two points: computation cost; key predistribution challenge • What is the major difference between HTTP 1.0 and 1.1? Why 1.1 makes such change? Knowledge Question Examples • What are the two major hash functions in use? – SHA-1 and MD5 • Using the notation in ch31.ppt, what are the meaning of: – H(m), KA-(H(m)), KCA-(KA+), KAB(m) • Full name of SMTP, FTP, RR, TLD? • What are the four types of DNS resource record? • Service port for DNS, SMTP, HTTP, SSH, Telnet. • SMTP basic commands for email compositing Calculation Problem Examples • Compute ciphertext using Cesar cipher • Compute ciphertext given transposition cipher key (ch30.ppt, P16-18) • If Alice wants to send a message m to Bob confidentially and wants Bob be sure that it is from Alice, what message format should be? Assume Alice and Bob knows each other’s public key beforehand. What if only integrity is required? • DNS setup and RRs for a new company (HW4) Excluding Contents • • • • • • Packet fragmentation SNR and dB concepts and computation Shannon and Nyquist theories Stop-Wait ARQ and go-back-N ARQ CRC computation Checksum computation