Reading from Blown to Bits for next class
To appreciate encryption, we must learn a bit about bits. We’ll start with Semmy’s Digital Encodings lecture notes.
What is the number of bitstrings of length n.
|n||2n||things to consider|
|16||65536||Common for “personal” computer in the 80’s|
|32||4294967296||Common for today’s computers|
Could cause problems in the year 2038
|56||72057594037927936||Number of DES keys|
|64||18446744073709551616||Number of Lucifer keys|
|256||~ 1.15 × 1077||Common for AES keys
Number of observable atoms about 4 × 1080
|2048||~ 3.2 × 10626||Common for RSA keys|
|4096||~ 1 × 101253||Hard RSA keys|
Is it possible that Edward Snowden really doesn’t know how to decrypt all documents he has?
- What is 42 in binary?
- What does the binary number 00100110 represent?
- Hexadecimal: as in The Martian
- Hexadecimal: as in HTML
- ASCII and Extended ASCII
- The CSCI 255 spreadsheet
Following instructions given in lab, do the following.
- Open a terminal session
- You can also try connecting to iotla.cs.unca.edu using ssh
- Create a directory called public_html/lab107
- Create a file public_html/lab107/hello.txt
- View http://www.cs.unca.edu/~yourname/lab107/hello.txt in your browser