Username: 
Password: 
Restrict session to IP 
Questions  |  score: 0  |  0.33 2.67 2.33 |  Solved By 65 People  |  4895 views  |  since Feb 12, 2023 - 01:04:47

CGX#4: Ascii Encoding (Encoding, Training, CGX)

ASCII Encoding
Hello future Hackers,

We have created the next lesson.
This time we talk about ascii encoding.
Again, the challenge is more informative and gives no points.

Happy Challenging!
- gizmore and x
Problem CGX#4
This lesson has an interactive problem:

72 101 108 108 111 32 71 117 101 115 116 46 32 83 111 108 117 116 105 111 110 58 32 120 85 104 86 108 120 112 120

The problem is randomly generated and is bound to your session.

Good Luck!
The WeChall Team
Your solution for CGX#4: Ascii Encoding
Answer
# CGX#4: Ascii Encoding

Computers can only work with numbers.
We need a mapping, for converting numbers to written characters, to display text to humans.
The [ASCII](https://en.wikipedia.org/wiki/ASCII)
[encoding](../README.md)
was one of the first encoding to solve this problem.


## ASCII

- 1 byte per character.
- Original 7 bit + 1 bit [checksum]()
- [ASCII Table](https://www.asciitable.com/)


## Other encodings
- C64 Screencode (A=1, B=2, ...)
- 8bit ASCII / extended ASCII
- Win ISO
- Unicode with UTF 8/16/32


## PHP Implementation
- number to letter (chr())
- letter to number (ord())
- string encodings in PHP
© 2023 and 2024 by gizmore and x