# CAMP 2020 Day 1- the beginning

It is Day 1 at CAMP 2020, and the first year that we are holding the program online. Since cyberspace shortened the distance between us, the Bard Math Circle received numerous applications from around the country. We see students’ excitement over running into old friends and connecting with new CAMPers in Zoom classrooms.

We distributed our CAMPers into the six groups: SIN, COS, TAN, SEC, CSC, and COT (trigonometry!) according to their grade level and the questions we sent out on the application form.

For the morning groups, students and our staff members had an early start of their day during summer. This year, our Math, Computer Science, and Art classes are designed to revolve around the theme cryptography.

After each group met their instructors, the math class introduced students to vocabularies like plaintext, ciphered or coded text, encode, decode, encrypt, decrypt, etc. The LOWERCASE stands for the plaintext, and the UPPERCASE is the cipher message. Things started to get heated when our teachers brought up a series of mathematical problems related to simple methods of cryptography: substitution, multiplication, keyword cipher, and the period problem. In a substitution cipher, each letter of the alphabet substitutes another letter (e.g., ROT-13: rotate by 13 places). On the other hand, in a multiplicative cipher, the number you multiply plays a crucial role in determining the cipher.

If we built a times-3 cipher that multiplies the numbers by 3. As an example, we encrypted the letter c. The number for on the cipher strip is 2, so they multiplied 2 times 3 and got 6. Since 6 is the number for g, they encrypted as G

After a fifteen minute break, we resumed for the art class. The cipher wheel is a circular device using two discs. In lowercase and uppercase letters, the alphabet is recorded on both discs, creating a key to decipher coded messages. CAMP director, Japheth Wood, had mailed the material along with the CAMP t-shirts to the students beforehand.

To generate an encoded message using their own cipher wheel, students first need to align the lowercase letter a with any number from 0 to 25 on the center of the wheel. Determining the key (the number) they are using, CAMPers encrypt the plain text according to the matching uppercase letters on the inner disc. Noah in the SIN group sent his classmates the following text:

ROVVY 10

According to his key: the number 10, we figured out that he said “HELLO.” The class also decoded a few messages pre-designed by the instructors. Chelsea, a senior instructor for the art section, shared her screen for a long encoded message. We notice that the letters K, Y, V are repeating themselves: these letters stand for “the” in her sentence: “the unicorn is the national animal of Scotland.”

During the CS class, students learned some basic necessary commands on Google Colaboratory: ord, chr, append, join, print, for/in, if/else, return, def, print, strings, lists. Further, CAMPers explored how each command works and proposed various questions on how to change the command on their copy of the shared document.

Approaching the end of day one, our junior staff planned various activities for their group tailored to students’ interests. Some led the classroom to further explore the topic they left off, and some invited CAMPers to play the SET game as a tradition of our program.