Two Brief Essays on Cryptography
For an interesting take on cryptography and why it works, read: https://popehat.com/2013/09/08/size-matters/
It may help you to know that Shīfu is "master." Shíjú could be "current political situation," and Qióng could be "poor," except that that latter two are used as names in the essay.
When you are done with that, read this: https://popehat.com/2013/09/06/nsa-codebreaking-i-am-the-other/