Understanding Computer Security: Encryption and Key Concepts
Understanding Computer Security
1. Securing Your Computer System
Computer security is the practice of protecting an entire computer system, including users, hardware, software, and files.
2. Understanding Encryption
Encryption is a method used to render a message unintelligible to users who do not possess the key. It ensures a secure means of communication for a specific group.
3. Manual Encryption Techniques
Here are three types of manual encryption:
- The Scytale (Bat Lycurgus): The sender writes the message
Understanding Computer I/O: Types, Transfer Methods, and Storage
Understanding Computer I/O
Human-Readable I/O
- Used for communication with the user
- Printers
- Graphical display terminals
- Screen
- Keyboard
- Mouse
Machine-Readable I/O
- Used for communication with electronic equipment
- Units of discs and tapes
- Sensors
- Drivers
- Activators
Communication I/O
- Used to communicate with remote devices
- Digital line drivers
- Modem
Data Transfer Rate
- There may be differences of several orders of magnitude between data transfer rates
Application
- A disc used to store files requires software support for
Computer Architecture: Components and Types
The Architecture of a Computer
Computer architecture encompasses all component parts, their function, and the communication between those parts that allow them to work together in a coordinated manner.
Solution Background: Von Neumann Architecture
In the Von Neumann architecture, the program is stored in memory along with the data. The computer reads data from memory and interprets it as either a program instruction or data. Having a single bus makes the response speed slower, as the system cannot
Read MoreBinary Numbers and Floating Point Representation
1. Binary Number Systems
Binary Basics:
Each digit (bit) is either
0or1.Binary numbers are used to represent all data in computers.
Example:
1011in binary is11in decimal.
Binary to Decimal Conversion:
Each bit represents a power of 2.
Example:
1011= 1×23 + 0×22 + 1×21 + 1×20 = 11.
Decimal to Binary Conversion:
Divide by 2 and record remainders.
Example:
11in decimal is1011in binary.
2. Encoding Integers
Unsigned Integers (B2U):
Represents non-negative numbers.
Range: 0 to 2w – 1 (where w is the
Supercomputers, Mainframes, and Other Computer Types
Supercomputer: Let’s explain the type of computer known as a supercomputer and its significance in modern computing. Supercomputers are the largest and fastest computers, capable of processing trillions of functions in seconds. These computers are primarily used for data-intensive and computation-intensive scientific tasks such as password encryption and decryption, weather forecasting, exploring the solar system, molecular modeling, etc.
Some of the advantages of using this type of computer are:
Read MoreHash Tables, Binary Trees, Graphs, Balanced Trees, Heaps & DP
Chapter 6: Hash Tables
What is a Hash Table?
A hash table is a data structure used to store key-value pairs efficiently. It uses a hashing function to compute an index (or hash) from the key, where the value is stored in an array-like structure.
1. Collisions
Collisions occur when two keys hash to the same index in the hash table. Hash tables must handle collisions to work correctly. Common methods for collision resolution:
- Chaining
- Each slot in the hash table holds a linked list of key-value pairs.
- When