Building Secure Password Generation Tools: My Tool npwg

The world is full of things that seem simple on the surface but are, in fact, surprisingly complex. Password generation is one of those things. You’d think, it is all about generating random characters. But the more you dig, the more you realize how much nuance there is, how many hidden pitfalls await the unwary. That’s how my project npwg started, not as a grand plan, but as a kind of intellectual itch.

The Conventional Wisdom is Wrong

The standard approach to password generation is often a mess. You have these rigid, inflexible policies that force users to create passwords that are both hard to remember and, ironically, often not very secure. The problem is that the focus is on rules, not on entropy. It’s like trying to build a sturdy house by just piling up bricks without understanding the underlying structure.

So, I started thinking, “What if we could build something that actually understands what makes a password strong, instead of just following some arbitrary checklist?” That’s where npwg came in.

The choice of Rust as programming language to bring my idea to code wasn’t just about performance, although that’s a nice bonus. It was about the eco-system which provides a lot, along with how Rust forces you to think about your code. Its memory safety guarantees aren’t just about preventing crashes; they’re about preventing subtle security flaws that can creep in when you’re not paying close enough attention.

Diving Deep: More Than Just Randomness

The real fun started when I began to explore the different ways you could generate passwords. It turns out there’s a lot more to it than just picking random characters. Homoglyphs, for instance, are characters that look alike, such as ‘O’ and ‘0’ or ‘l’ and ‘1’, which can easily lead to confusion in passwords. Effectively addressing this issue requires excluding or substituting these characters to enhance both security and usability. Then there are Shell-Safe Characters, designed for system-generated passwords, ensuring that special characters won’t cause issues in shell environments—a critical detail that allows passwords to remain functional across different contexts. Finally, there’s Diceware, a method for generating memorable and secure passphrases by combining simple words, offering an excellent balance between strength and ease of recall.

The Interactive Experiment

Most command-line tools are about function, not interaction, but I wanted to make npwg something that people could actually use, even if they weren’t security experts. The interactive mode was an experiment in making complex ideas accessible, showing that good tools should be both powerful and approachable. What truly surprised me was how much people’s needs varied, some needed passwords that conformed to very specific rules, while others wanted maximum randomness. This made customization an essential feature, reinforcing the idea that the best tools adapt to the user, not the other way around. And while Rust’s efficiency made npwg fast, speed wasn’t the primary goal; the focus was on building something correct and secure, with performance as a natural byproduct of doing things right.

The Future is Open

npwg is open source because I think it’s important to share this kind of work. Security shouldn’t be a black box. It should be something that we can all understand and contribute to.

To me, npwg isn’t just another password generator; it’s a statement, a deep dive into the true essence of password security. It challenges the flawed “conventional wisdom” that often governs security practices, showing that the real answers come from dissecting the problem to its roots. It’s the idea that the most exciting and meaningful projects often start with a simple, bold question: “What if we turned this on its head and did it differently?”

If you want to learn more about npwg, you can find it on GitHub. The link is under the Projects page. And if you want to contribute, I’d be thrilled to have you on board. After all, the best way to build a secure future is together.