Serguey Asael Shinder – IT Professional

Early in my career, I was clever enough to be dangerous. I looked at a cryptography problem, understood the algorithm well enough to follow it, and thought: I can implement this myself. It looked like a puzzle, and I was good at puzzles.

It is not a puzzle. It’s a minefield with a friendly-looking surface. My implementation was, as far as I could tell, correct — it produced the right outputs, the tests passed, it looked done. What I couldn’t see were the ways it quietly leaked: subtle timing differences, a value I reused that should never be reused, edge cases I didn’t even know were categories of attack. The math was right and the implementation was full of holes I lacked the expertise to imagine, let alone test for.

What saved me was an experienced engineer who saw what I was doing and gently talked me out of it. Not because I wasn’t smart, he said — but because this particular domain has an attack surface no single person can cover. The vetted library I was about to replace had been written by specialists and then attacked by thousands of people for years, and had survived. My weekend version had been reviewed by exactly one optimistic person: me.

That reframed something important. Using the boring, battle-tested library instead of my own clever code wasn’t a failure of ambition. It was the actual expert move. The clever thing in cryptography is refusing to be clever.

I’ve carried that humility well beyond crypto. There are domains where the right instinct isn’t to prove you can build it yourself, but to recognize the depth of what you don’t know and stand on the work of the people who spent their careers there.

– Serguey Asael Shinder