Notes on codes, projects and everything
To test our understanding in RSA public key cryptosystem, we were being asked to develop a computer program to demonstrate the cryptosystem. The whole system consists of a random number generator, an encoding module that is able to encode characters into numbers, an encryption module as well as decryption module and finally an RSA cryptosystem cracking module.
The program is written in Microsoft® Visual C6, the reason why Visual C6 is being selected is because we wanted to do something simple. There is no GUI being implemented as we wanted to spend more time in enhancing the program.
To generate random number, we used Blum-Blum-Shub random number generator as we found it to be the easiest to implement.
I happened to find a general solution suggestion on a Wikipedia entry when I was browsing the internet around to find a solution to modular exponential problem. The code snippet posted on the wikipedia entry claimed that it came from …
RSA is a cryptosystem …
After publishing the previous note on setting up my development environment, I find myself spending more time in the CLI (usually via SSH from host). Then I find myself not needing all the GUI apps in a standard Ubuntu desktop environment so I went ahead and set up a new environment based on Ubuntu Quantal server edition beta-1. For some reason my network stopped working and didn’t really want to spend time finding out the cause, so I reinstalled everything again today using the final installer, as well as the updated Virtualbox 4.2.6.
Ever wanted to find the number of days between two dates without counting weekend (Saturdays and Sundays)? In PHP you typically needs to do a lot of calculation and a lot of factors needs to be considered. Therefore, in the end you will end up having a whole bunch of code that you will probably start asking yourself whether you are programming a web-calendar or something similar.
In the last part, I implemented a couple of primitive functions so that they can be applied in the following chapters. The second chapter of the book, is titled “Do it again, and again, and again…”. The title already hints that readers will deal with repetitions throughout the chapter.
After being frustrated of not getting consistent and accurate result via standard DOM methods especially
html_element.setAttribute('key', 'value');, I came across some YUI library components that provides abstractions to various DOM methods. Some interesting DOM-related tools covered in this post are