EECS 354
Homework 1
Student Name: Student NetID:
Submission instructions: please email your solutions in a Word or PDF file to HYPERLINK “mailto:[email protected]” [email protected] by 11:59pm 11/10 (Tue).
Please classify each of the following as a violation of confidentiality, integrity, availability, authenticity, or some combination of these:
John copies Mary’s homework.
Paul crashes Linda’s system.
Gina forges Roger’s signature on a deed.
Suppose that you are recommending usage of crypto standards to your CTO for the next generation of IT products in your company. The products aim for the market of the next five to ten years. For symmetric cipher, you will recommend ________________________, for asymmetric cipher, you will recommend ________________________, and for secure hash functions (a.k.a., message digest), you will recommend ________________________________.
Based on your answers above, please fill in the table below to compare the three crypto mechanisms.
Symmetric Cipher
Asymmetric Cipher
Message Digest
Key length
Block size (bits)
Output size (given input size n=220 bits)
Basic generic structure
N/A
Message digest are reasonably fast, but here’s a much faster function to compute. Take your message, divide it into 128-bit chunks, and XOR all the chunks together to get a 128-bit result. Do the standard message digest on the result. Is this a good message digest function?
What is the traditional difference between viruses and worms? What is the key difference between worms and botnets?
The Internet is, slowly, transitioning from the version of the TCP/IP protocol suite currently in use IPv4 to a new version, IPv6. Unlike IPv4 IP addresses, which are 32 bits long (e.g., 192.168.10.1), IPv6 IP addresses are 128 bits long (e.g., 2001:1890:1112:0001:0000:0000:0000:0020).
a. Consider random-scanning Internet worms. These worms spread by choosing a random IP address, connecting to any host answering to that address, and attempting to infect it. Is the random-scanning strategy feasible if the Internet switches from IPv4 to IPv6? Why or why not?
b. On the IPv6 Internet, try to give three different ways that a worm, executing on a compromised computer, can discover IP addresses of other hosts to try to infect.
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