THCON-2k24
base64-custom THCON 2024
Challenge
Understanding the challenge
How base64 works
It takes every single letter of the word.
Then it converts it into decimal.
Then the decimal is converted into binary having length 8 bits.
Then the binary is regrouped with every binary having length of 6 bits.
Then the binary is converted into decimal.
Then the decimal is converted into another character according to base64 index table.
What is different in this base64custom
It is told that sextets are changed into quintuplets which means in the 4th step instead of 6 bits the length was 5 bits.
Contents of message.txt
KREEGTaOPNRDIcbFGYaFeMLTLcaHOMbTGBWWKXbJNZXGSdDd
Solution
It is same as base32 but with a condition that all the alphabets will be according to base64.