In debates about national security, it is often said that governments can’t effectively ban encryption because it’s not any particular piece of software, it’s just math.

RSA is not in the Python standard library, and requires various functions which I’d naturally go looking for in external libraries (e.g.

This seemed like a good challenge for two reasons: What project to pick? I decided to have a go at implementing the RSA cryptosystem for asymmetric key cryptography, a pretty fundamental part of modern computer security. This is a challenge, because while Python supposedly ships with all the basic stuff you should need (‘batteries included’), in practice this is arguably not true. the Standard Library, no external packages). Armed with nothing more than a few scribbled notes and old slides covering undergraduate-level CS, and using only basic Python (i.e. Someone whose programming has always been a little shoddy and now very out of practice. While I don’t think this is actually the answer to the above problems, it could be a fun exercise to see how many of the basic building blocks of modern computing could be re-created from scratch. In some cases this can lead to an unexpected global mess, such as the time when a developer of several popular NPM libraries pulled them from the package management system, breaking the ‘ Jenga tower of Javascript‘. This is great in many ways, because whatever you want to do, someone else has probably already done it better and more secure.īut it also means that most applications are dependent on code written and maintained by other people.

I’ve also been thinking about how the development stack for most programming languages is so dependent on a byzantine labyrinth of third party libraries and packages. So I decided to set myself a little project to get back into it. This is not unusual for someone working in CS, especially those of us at the ‘softer’ edges.

Despite working in computer science, these days I barely have the need to write any code in my day-to-day work.

Python rsa decryption