SUNY Geneseo Department of Computer Science
“The Beale Papers”
Tuesday, March 4
Intd 105 13, Spring 2014
Prof. Doug Baldwin
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Misc
Midterm is next Tuesday (Mar. 11)
- Covers
- Factual material we’ve looked at since start of semester (e.g., substitution ciphers, book ciphers, ethics, plagiarism, etc.)
- Writing skills in short essays or problems
- Short answer + short essay
- Full class period
- Open books, notes, online references; closed person
- May write on computer and email me answers
- Either turn in on paper or by email, but not both
- You are responsible that I receive what you want graded (check before leaving)
Questions?
The Beale Papers
Summary
- Stranger (Beale) visits inn, comes back a year later and leaves a locked box with the owner, who is known for his integrity
- Owner instructed to open box if no word comes from Beale in next 10 years
- Many years later, he opens box, finds a letter and 3 encrypted messages with no key
- Letter explains that encrypted messages give the location, description, and owners (or next of kin) of a treasure found in New Mexico and buried in Virginia
- Tries to decrypt messages and fails
- Passes job on to a friend on his deathbed
- Friend eventually decrypts second message, describing treasure and its general location
What is the treasure worth today?
- Gold: $1337 / oz, 2921 lbs = 46736 ounces, worth about $62 million
- Silver: $21.16 / oz, 5092 lbs = 81472 ounces, worth about $1.7 million
How does the cipher work?
- Book cipher
- Each number in ciphertext is the position number of a word in some text
- Corresponding plaintext character is the first letter of that word
Try it
- Cryptography lessons
- Don’t leak even small bits of information; little hints at how a cipher works can help people break it
- Not using a cipher “right” can seriously compromise security (e.g., using the same word for every occurrence of a letter turns super-secure book cipher into an easily broken substitution cipher)
- Protecting and communicating keys is hard
Next
Peer critiques of race essay revisions
Bring 3 printed copies
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