This will be a closed-book exam.
You may, however, use one new 3"-by-5" note card,
last exam's note card, and a calculator.
Cryptanalysis aids, such as tables of characteristic frequencies,
will be provided.
You will have the entire class period to work the exam,
but you should not need all that time.
You should be prepared to solve problems of the following kinds.
Encipher a message by...
keyword-mixed monoalphabet
symbol-based monoalphabet
Vigenere polyalphabet (with normal plain and cipher sequences)
given a keyword.
Decipher a "crypt" that was enciphered by...
keyword-mixed monoalphabet
symbol-based monoalphabet
Vigenere polyalphabet (with normal plain and cipher sequences)
with alphabets selected by a keyword
Solve (cryptanalyze) an enciphered message enciphered by...
keyword-mixed monoalphabet
You should be able to this in both these cases:
crypts with word divisions preserved ("Aristocrats")
crypts without word divisions ("Patristocrats")
symbol-based monoalphabet
Vigenere polyalphabet (with normal plain and cipher sequences)
with alphabets selected by a keyword
...without knowing the key in advance.
Demonstrate your ability to carry out preliminary cryptanalysis tasks
such as ...
preparing a monoalphabetic frequency distribution
calculating an index of coincidence
preparing a trigraphic frequency distribution
developing "Kasiski" (repeated sequence) evidence
distinguishing monoalphabets from polyalphabets
determining the length of the keyword for polyalphabetic
encipherment
using "slides"/matching frequency distributions
... and using the results.
Primary references: your class notes and Sinkov chapters 2 and
3 (sections 3.1-3.4)
Secondary reference: Barr sections 2.3, 2.5, 2.7