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
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Packet fragmentation
SNR and dB concepts and computation
Shannon and Nyquist theories
Stop-Wait ARQ and go-back-N ARQ
CRC computation
Checksum computation