CGX#15: Still Binary (Encoding, Training, CGX)
CGX: Still Binary
Hello future Hackers,
Back in the Days, ASCII was only 7 bit.
The 8th bit, in particular the MSB was used as a check bit, the number of set bits modulo 2.
In challenges, you might encounter a stream of 0 and 1 using only 7 bits per byte.
A hint that this technique is used, might be when the number of bits is divisible by 7.
Your task now is to convert a stream to ASCII.
Greetings
- gizmore and x
Back in the Days, ASCII was only 7 bit.
The 8th bit, in particular the MSB was used as a check bit, the number of set bits modulo 2.
In challenges, you might encounter a stream of 0 and 1 using only 7 bits per byte.
A hint that this technique is used, might be when the number of bits is divisible by 7.
Your task now is to convert a stream to ASCII.
Greetings
- gizmore and x
| ( ! ) Fatal error: Cannot redeclare class WC_CryptoChall (previously declared in /home/gizmore/www/gwf3/core/module/WeChall/WC_CryptoChall.php:6) in /home/gizmore/www/gwf3/core/module/WeChall/WC_CryptoChall.php on line 6 | ||||
|---|---|---|---|---|
| Call Stack | ||||
| # | Time | Memory | Function | Location |
| 1 | 0.0002 | 433656 | {main}( ) | .../index.php:0 |
| 2 | 0.0092 | 1256432 | WC_CodegeexChallenge->getProblemBox( ) | .../index.php:49 |
| 3 | 0.0092 | 1256432 | WC_CodegeexChallenge->getProblem( ) | .../WC_CodegeexChallenge.php:257 |
| 4 | 0.0092 | 1256504 | WC_CodegeexChallenge->parseProblem( ) | .../WC_CodegeexChallenge.php:172 |
| 5 | 0.0092 | 1256920 | include( '/home/gizmore/www/gwf3/www/challenge/codegeex/02_00_encodings/02_04_still_binary/flag.php ) | .../WC_CodegeexChallenge.php:337 |
PHP Fatal Error(1): Cannot redeclare class WC_CryptoChall (previously declared in core/module/WeChall/WC_CryptoChall.php:6) in core/module/WeChall/WC_CryptoChall.php line 6
Backtrace starts in [unknown file] line ?. GWF_Debug::shutdown_function() core/inc/util/GWF_Debug.php line 109. GWF_Debug::error_handler().... core/inc/util/GWF_Debug.php line 180.