Ciphers

Test yourself

Ciphers

Some ciphers are harder to crack than others. Pigpen, Vigenere and rail fence ciphers are stronger than Caesar ciphers.

Pigpen cipher

The pigpen cipher is a simple substitution cipher.
Rather than replacing letters with other letters, the pigpen cipher replaces letters with symbols.
The image above represents the word "The".

Vigenère cipher

Vigenère cipher is a polyalphabetic substitution cipher.
Multiple Caesar cipher keys are shared between two parties.
The first letter is encrypted using the first key, the second with the second key and so on until all of the text is encrypted.
This protects against frequency analysis.

Rail fence cipher

Rail fence cipher is a transposition cipher.
In the rail fence cipher words are written out letter-by-letter in a zig-zag pattern.
Each row is then read, which scrambles up the letters.
If the recipient knows how many rows there originally were, then they can decrypt the message.

1Problem Solving

1.1Algorithms

1.1.1Algorithm Thinking

1.1.2Interpreting Algorithms

1.1.3Expressing Algorithms - Pseudocode

1.1.4Expressing Algorithms - Flow Charts

1.1.5Correcting Algorithms

1.1.6Completing Algorithms

1.1.7Search Algorithms

1.1.8Linear Search

1.1.9Binary Search

1.1.10Sort Algorithms

1.1.11Bubble Sort

1.1.12Merge Sort

1.2Decomposition & Abstraction

1.2.1Computational Thinking - Abstraction

1.2.2Computational Thinking - Decomposition

1.2.3End of Topic Test - Algorithms

2Programming

3Data

3.1Binary

3.1.1Number Bases

3.1.2Negative Binary Numbers

3.1.3Binary Addition

3.1.4Binary Shifts

3.2Data Representation

3.2.1Representing Text

3.2.2ASCII

3.2.3Unicode

3.2.4Representing Images

3.2.5Representing Sound

3.3Data Storage & Compression

3.3.1Capacity

3.3.2Calculating Capacity Requirements

3.3.3Data Compression

3.3.4Run Length Encoding

3.4Encryption

3.4.1Encryption

3.4.2Caesar Cipher

3.4.3Ciphers

3.5Databases

3.5.1Databases

3.5.2End of Topic Test - Data & Representation

4Computers

4.1Machines & Computational Modelling

4.1.1Computational Models

4.1.2Input-Process-Output Model

4.2Hardware

4.3Logic

4.3.1Binary Systems

4.3.2Logic Circuits

4.3.3Boolean Logic

4.3.4End of Topic Test - Logic

4.4Software

4.4.1Operating Systems

4.4.2User Interface Managetment

4.4.3Memory and Process Management

4.4.4File Management

4.4.5Device Management

4.4.6User Management

4.4.7Encryption Software

4.4.8Defragmentation Software

4.4.9Data Compression Software

4.4.10Backup Software

4.5Programming Languages

4.5.1High Level Languages

4.5.2Low Level Languages

4.5.3Translators - Compilers

4.5.4Translators - Interpreters

4.5.5Translators - Assemblers

4.5.6End of Topic Test - Translation & Representation

5Communication & The Internet

5.1Networks

5.2Network Security

5.2.1User Access Levels

5.2.2Encryption

5.2.3Protecting Against Malware

5.2.4Firewalls

5.2.5Forms of Attack

5.2.6Penetration Testing

5.2.7Malware

5.2.8How Malware Spreads

5.2.9Social Engineering

5.2.10Protecting Against Social Engineering

5.2.11Phishing

5.2.12Network Administration

5.2.13Network Forensics

5.3The Internet & the World Wide Web

5.3.1IP Addresses

5.3.2Types of IP Address

5.3.3MAC Addresses

5.3.4Packet Switching

5.3.5How Do Packets Get Routed?

5.3.6Did My Data Arrive Safely?

5.3.7The Internet

5.3.8URLs

5.3.9DNS

5.3.10Web Hosting

5.3.11End of Topic Test - Security

6The Bigger Picture

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