That's like saying "being a vehicle is how a lot of cars work"; the reasons on why the cipher is flawed are a bit more specific than that.

As for the elitist arrogance, whilst I'm sure these exist in other security-related interactions across the world, the interaction that's the subject of this thread involves plenty of polite comments that

- point out author's lack of background knowledge - refer to short-cut theorems that help evaluate a cipher, implying the author should learn about these theorems - explicitly tell the author to learn about these theorems

In response to this, the very first reply the author gives is "It almost sounds like you have had your soul crushed by bureaucracy over the years and have lost all passion for this field. I hope that's not true."

Yeah, however much "arrogant" you interpret the security people in this thread to be, it's only fair to interpret the OP (Mark McCarron) to be 2-3x as arrogant.

Fortunately most books don't have an opinion about who is reading them.

They did in fact encourage him to learn and even pointed him to various entry-level resources and mailing lists.

I am honestly very triggered by any tone of elitism in the sphere of intellectual or professional pursuits. It's not just in tech - just try googling 'DIY HVAC Repair'. Now, I don't advocate partaking in activities which are legitimately dangerous without training and certification (e.g. charging an HVAC system with freon or operating a crane), but when all you are trying to do is replace a contactor in your HVAC system and you get a wall of "DIY is not allowed here" when asking basic questions, it really puts some hate into your soul. Cryptographers give me the exact same sensation with their 'no DIY' rhetoric.

At the end of the day for me, it mostly boils down to some ulterior agenda which seeks to keep competition or perceived threats to the incumbents' control at bay.

Does the NSA have a vested interest in most technology workers being able to competently roll their own encryption schemes? From my very jaded political perspective, I would say absolutely not. It arguably makes their mission exponentially harder if they have to deal with novel approaches to securing communications. They would probably prefer everyone just use ECC with their hand-selected curve parameters.

> It arguably makes their mission exponentially harder if they have to deal with novel approaches to securing communications.

NSA and GCHQ would absolutely love it if people used novel approaches to cryptography and started kludging together dumb crypto systems. This makes their stated mission considerably easier.