Lamp @sotaroon - Tumblr Blog

cherryhatter-deactivated2015072

KICK THE CAN!

Let’s play the biggest game of kick the can on the internet.

To kick the can, reblog it. I wanna see how long this can go on for.

the oldest reblogs for this post that i can find are from january 2nd of 2013. this can has been getting kicked around tumblr for almost 13½ years now

drtanner

And yet somehow this is my first time kicking it!

There is no ferret emoji 🥲

#lps #ferret #my art

wtf-scientific-papers

Wang and Lai (2014)

gemstone-gynoid

squipdop

every single fucking thing on earth exists solely to put a dent in your newly applied nail polish

yellowtrinity

9ish persons

lleyksie

bunnies ! !

dykemd

what a typical wednesday looks like

athingofvikings

Years and years ago, I read a book on cryptography that I picked up because it looked interesting--and it was!

But there was a side anecdote in there that stayed with me for more general purposes.

The author was describing a cryptography class that they had taken back in college where the professor was demonstrating the process of "reversibility", which is a principle that most codes depend on. Specifically, it should be easy to encode, and very hard to decode without the key--it is hard to reverse the process.

So he had an example code that he used for his class to demonstrate this, a variation on the Book Code, where the encoded text would be a series of phone numbers.

The key to the code was that phone books are sorted alphabetically, so you could encode the text easily--picking phone numbers from the appropriate alphabetical sections to use ahead of time would be easy. But since phone books were sorted alphabetically, not numerically, it would be nearly impossible to reverse the code without exhaustively searching the phone book for each string of numbers and seeing what name it was tied to.

Nowadays, defeating this would be child's play, given computerized databases, but back in the 80s and 90s, this would have been a good code... at least, until one of the students raised their hand and asked, "Why not just call the phone numbers and ask who lives there?"

The professor apparently was dumbfounded.

He had never considered that question. As a result, his cipher, which seemed to be nearly unbreakable to him, had such an obvious flaw, because he was the sort of person who could never coldcall someone to ask that sort of thing!

In the crypto book, the author went on to use this story as an example of why security systems should not be tested by the designer (because of course the security system is ready for everything they thought of, by definition), but for me, as a writer, it stuck with me for a different reason.

It's worth talking out your story plot with other people just to see if there's a "Why not just call the phone numbers?" obvious plot hole that you've missed, because of your singular perspective as a person. Especially if you're writing the sort of plot where you have people trying to outsmart each other.

athingofvikings

Side note:

The number one response to this post is something I should have seen coming, given that this is the Social Anxiety Website:

"What do you mean, call the number!?"

This anecdote was from the 1970s or 1980s. Coldcalling numbers and getting "Family name] residence, [name] speaking" was the typical interaction, at which point you could just easily say, "Oh, sorry, wrong number" and hang up, with no further investment of time or effort needed. So if you were a spy or counter-intelligence agent or anyone invested in breaking a code, yeah, you'd call those numbers in a heartbeat back then, and once you got enough letters, you could start doing frequency analysis and break the code, and failing to recognize that element was the failure of the professor, who had come up with this code as a "hard to break" example for his students.

Now, I recognize that most people here aren't in either of those mindsets, but still...

I just find it funny and more than a little ironic that the number one response to this anecdote are people proving the point of the anecdote in that they don't look past their own immediate perspective and outlook, and missing the point:

The professor had designed a sample code for his class with the intention that it would be hard to break. However, it had an obvious hole in its ability to resist being broken, and the professor had overlooked this hole. And the reason why he overlooked it is because the professor was the sort of person who didn't just call people, and thus it didn't occur to him that it would be vulnerable to that form of brute-force cryptographic attack.

And that is the core point of the anecdote.

And I just find it amusing that so many out of the thousands of reblogs have fixated on that detail.