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      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
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PDF secret sharing

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Tdawg30

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Finally exams are done and I have (barely) survived!

Even though classes are over for me, I am continuing to work on a project for one of my professors, who has an interest in data security/privacy. What the work is, is to attempt to create a program that can encrypt and decrypt pdf files using Shamir's Secret Sharing effectivly and efficiently.

If you don't know what Secret Sharing is regarding to encryption it is the following: We take a 'secret' and generate an arbitrary number of shares from it, which can be then distributed safely accross what ever medium. Individually these shares are useless, but when a specific number of shares, k, are combined, they reconstruct the original secret. An easier way to think of it is say you have a switch to deploy a bomb, however it is kept protected by locks. 5 people have keys for the locks, therefore you need 3 of the people to use their keys to open the 3 locks in order to flip the switch. Read the Wiki for more details on the technique. In my project, each letter in the PDF document is treated as a secret, and split into 5 shares. 5 pdf documents are created to hold the corresponding shares for the entire document and 3 share files are required in order to reconstruct the original document. Reconstruction is done by calculating Lagrange basis polynomials. Again read the wiki for more info.

One problem that arises is that this technique is weak to frequency analysis attacks. This means that characters are directly mapped to a different character. So so say we have the letter 'a' as a secret to be shared then as example the following secrets are generated for it:

Secret 1: b
Secret 2: D
Secret 3: j
Secret 4: 8
Secret 5: y

This seems fine as there is no way someone looking at those 5 shares could figure out our secret is 'a'. However the problem lies in the fact that EVERYTIME the letter 'a' is shared in our document it will appear as 'b' in secret 1, 'D' in secret 2, etc. This is fixed by modifying how we create the shares which now uses the sumation of the degrees of our polynomials as the functions for computing secrets.

Secret sharing is not restricted to text, since to calculate text values, we use the numerical equivilant and share that value, what is stopping us from sharing images and sharing the RGB values? nothing at all! If we take a pixel from an image, and create shares of the R, G and B values of that pixel, our image is virtually destroyed in the shares, and can be reconstructed in the same manner as text is. This is however more computationally expensive as instead of performing one 'sharing' operation per character, we are performing 3 operations for every pixel.

As for the progress of the project, I have implemented the text features fully, and currently am working on image sharing. Unfortunately taking a 2~ week break for exams has made me feel rusty on the project and I REALLY wish I had commented my code better at the time sleep.png

Anyways, I hope I enlightened you slightly on a strong encryption technique which isn't too hard to implement in code yourself as the computer will deal with all the actual math for you! If you have any questions feel free to ask, time for me to re-aquaintent myself with my code!

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