Terminology and Cryptology
1.Classify each of the following as a violation of Confidentiality, Integrity, Availability, or some combination of these:
a. John copies Mary’s homework.
b. Paul crashes Larry’s system.
c. Carol changes the amount of Fred’s payroll check from $100 to $1000.
d. Gina forges Roger’s signature on a legal document.
e. Linda registers the domain name “AddisonWesley.com” and refuses to let the publishing house buy or use that domain name.
f. John gets Peter’s credit card number and has the credit card company cancel the card and replace it with another card with a different account number.
g. Henry spoofs Jane’s IP address to gain access to her computer.
2. Suppose Alice and Bob have public keys in a file on a server (that is, when Alice wants to use Bob’s public key, she gets it from the server rather than storing everyone’s key locally). They communicate regularly using authenticated confidential messages. Eve wants to read the messages but is unable to crack the private keys. However, she is able to break into the server and alter the file containing the public keys. How should Eve alter the file so that she can read confidential messages from Alice and Bob and can forge messages from them? How might Alice and Bob detect Eve’s subversion?
3. Suppose Alice, Bob and Carol want to use secret key encryption to authenticate to each other. If they all use the same key, then Bob could impersonate Carol to Alice (any one of the three could do this). Suppose instead that each had their own secret key, so that Alice uses KA, Bob uses KB and Carol uses KC. Is this more secure (in the sense that it solves the impersonation problem) than having them all use the same key?
4. Explain the following terms (from the readings and the slides) with one or two sentences: cryptanalysis; symmetric encryption; DES, AES, and RSA; threats and vulnerabilities; denial-of-service attacks; browser cookies; spoofing; root compromise; firewalls.
5. Using a web resource such as or look up recent computer virus outbreaks. How many virus incidents have occurred in the last week? (Include where you got the information).