Frequency Analysis for Indie Game ARG

Frequency Analysis for Indie Game ARG

Category
Just for Fun
Published
2017
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A friend of mine recently released a demo for their new studio’s second title, Heartbound.

Aside from being a fantastic developer, their cryptographic prowess has secured them multiple DefCon Black Badges.

Along with the game's release, they created an ARG puzzle that you can check out here: http://gopiratesoftware.com/games/Heartbound/TheLightBeckons/

Spoiler Warning: If you’d like to work through the challenges yourself, I’d avoid reading the rest of this article.

One of the challenges requires the usage of the runic glyphs as seen on multiple pages throughout the ARG, though I wasn’t sure how I would apply them.

My initial thoughts led me to believe it was simply a public font and many hours of googling resulted in even more confusion.

A series of books titled “Our Mathematical World” recently launched here in the UK. One of the cryptography-focused issues brought up the usage of frequency analysis to decode caesar cyphers along with unknown glyph text. At that point, I immediately thought back to the puzzle. The book even provided this neat little table:

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We’ll start with this sample of all glyphs and search for the most frequent ‘characters’. To narrow this down further, we can check the glyph positions and reference them with letterfrequency.org.

The site identifies the most common first letter in the English language as ‘T’. Under this assumption, I went with what I’ve coined as the ‘table’ glyph. I’ve removed the background and marked our guess.

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Luckily there are a couple of two-letter words on the right set of glyphs; this makes it easier to narrow down possible characters.

The most common second letters are as follows:

h, o, e, i, a, u, n, r, t.

We can rule out ‘th’, and assume that the F glyph is ‘o’ to form ‘To’.

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From here it’s a case of following similar cases and using word finder tools to aid character assumptions. I’ve also added a key to help us form words later on.

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‘th’ being the most common two-letter combination made eyeing certain words/assumptions much easier, providing a larger sample size for future reference. There isn’t enough data to complete a custom alphabet, much to the dismay inner completionist.

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It was a super fun topic to look into. However, these days frequency analysis has lost most of its purpose in the realm of cryptography, only bearing relevance to the odd archaeologist or computer science class.

Bonus! My original messy walkthrough of the puzzle

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