Cryptography

Just before Thanksgiving break, I asked you to spend some time reflecting on lessons you’ve learned this semester about keeping secrets, given all the examples of cryptography and cryptanalysis we’ve seen this fall. Here’s what you came up with:

(Click on a photo to see a larger version.)

Here’s the same list, without all the nonlinear connections:

• You can’t keep secrets forever.
• Someone will break your cipher.
• You don’t know how clever the enemy is.
• Change ciphers frequently.
• One of your allies will screw up / betray you.
• Minimize errors through simple systems.
• Keep your circle of allies small. (Trust no one few.)
• Persistence / computing power will defeat you.
• Assume the worst. Double check.
• Use discretion in your plaintext.
• Kerckhoff’s Principle: The strength of your system shouldn’t depend on keeping its mechanics secret.
• Schneier’s Principle: Use a system lots of people have tried to break.
• Prioritize your secrets. Which secrets? From whom?
• Minimize ciphertext.

Be sure to draw on these lessons learned in your final papers on practical cryptography!

From last week’s brainstorming sessions for the Practical Cryptography class project…

What topics might we include in this guide? What do you want to learn about? What might your fellow students be interested in learning? What should they know about cryptography?

• Deep Web and privacy
• University censorship
• Online shopping security
• Phishing: VUIT, sports
• School tech policies
• Take advantage of / not get taken advantage of
• University data mining
• Online / cell phone tracking
• Twitter hacking

What tools might we use to produce this guide? Diigo, WordPress, Twitter, others? Consider both production and distribution phases.

• Twitter: for publicity, mention @vanderbiltu
• WordPress: Dedicated site and URL
• Diigo: topic ideas, shared references

Related: How should we tell Vanderbilt students about the guide? How can we get the word out, either during or after production?

• Twitter
• Pyramid scheme
• Some kind of event re: 1 or more topics
• Email all students?
• Tree posters with QR codes
• Commons email
• VU Facebook / VU News
• Hustler

What timetable should we follow to produce this guide? Notable dates: 11/24-28 is Thanksgiving Break. 12/3 is the last day of classes. 12/6 is the date of our “final exam.”

• Topics by Monday, November 17th
• Spring: (more) publicity

How might we use class time productively over the next few weeks?

• Discuss / brainstorm topics
  Writing days (e.g. “Can you read this?”)

You’re writing a guide to practical cryptography. Let’s hear some possible chapter titles.