CHAPTER 2 · 3 lessons · 39 exercises
Security
Encryption and hashing, how someone proves who they are, and how attacks work and get stopped.
Once you get to the point of letting other people use what you built, this becomes unavoidable: how you look after passwords, how you protect the traffic, and what you should be suspicious of.
It covers the difference between shared keys and public keys, hash functions, digital signatures and certificates, and the well-known attacks such as SQL injection and cross-site scripting along with what stops them. It is also the field the exam asks about most.
Lessons in this chapter
Encryption and hashing
- 04Two ways to encryptLock and unlock with the same key, or use a matched pair. How the keys get handed out, how many you need, why both get combined, and the calculation you cannot run backwards.Go to the exercises
Proving who you are, and certificates
- 05Proving you are who you sayA different job from hiding the contents. Who wrote it, whether it was altered on the way, and whether that key is genuine. A tour of the tools for checking.Go to the exercises
How attacks work and get stopped
- 06How attacks work and get stoppedWhere the holes in your own code are. The classic attack methods, the kinds of malware, and where each gets stopped.Go to the exercises