Author: Administrator

Hashing Algorithms for Storing Sensitive Data


More and more online systems such as e-commerce websites, online banking apps, or social networks need to access some sensitive data about you including your password, your credit card details and more recently, some biometric data (e.g. for fingerprint authentication

Hashing Algorithms for Memory Addressing


In this blog post, we will investigate the use of hashing algorithms to quickly locate a record in a large database. Let’s consider the database of members of a social network such as Instagram, Twitter or Facebook. Every time the

Recursive vs. Iterative Palindrome Check


For this challenge we will investigate two algorithms used to find out if a word is a palindrome or not. The first algorithm will use an iterative approach, the second algorithm will use a recursive approach. Iterative Approach An iterative

Blackbeard’s Hidden Treasures


The period of the late 17th and early 18th centuries is known as the Golden Age of Piracy. During this period the most notorious and the most feared of all pirates was Blackbeard. There are many legends based around Blackbeard’s

Blackbeard’s Treasure Map


We have all heard of the famous English pirate called Blackbeard who sailed the seven seas during the XVIII century. Through his numerous acts of piracy, Blackbeard accumulated a huge collection of riches including golden coins, jewels, golden plates and

The Pigpen Cipher


The Pigpen cipher (a.k.a. tic-tac-toe cipher) is a geometric substitution cipher, which exchanges letters for symbols which are fragments of a grid. Secret Message Using the key provided on the right, can you decode the following secret message?   Pigpen

The Rail Fence Cipher

A Rail Fence Cipher with 4 "rails" (Key = 4)

The rail fence cipher (sometimes called zigzag cipher) is a transposition cipher that jumbles up the order of the letters of a message using a basic algorithm. The rail fence cipher works by writing your message on alternate lines across

Semaphore Code Using Python Turtle


Flag semaphore is a telegraphy system conveying information at a distance by means of visual signals with hand-held flags. Information is encoded by the position of the flags. The current flag semaphore system uses two short poles with square flags,

Is my credit card valid?


In this challenge we will use the Luhn Algorithm to check if a debit card or credit card number is a valid card number. This method is used every time you scan or enter your credit card number (e.g. when

Cryptographic Challenge: Base64 to Hex


Extension Task Using the same approach, we can encode message in a range of encoding schemes such as Hexadeximal (4-bits per character), Base32 (5 bits per character), Base64 (6 bits per character), Extended ASCII (8 bits per character). You can