BASE FFFF+1: Decoding Beyond Base64

The “BASE FFFF+1” challenge takes the familiar concept of base64 encoding and elevates it to a new level. The challenge hints at an encoding technique involving a Chinese string.

Challenge: Base FFFF+1
Category: Warmups
Difficulty: easy
Author: John Hammond

Download the file(s) below.
Attachment: Base FFFF+1
You can use this Base 65536 Decoder

Description:
Maybe you already know about base64, but what if we took it up a notch?

鹎驣𔔠𓁯噫谠啥鹭鵧啴陨驶𒄠陬驹啤鹷鵴𓈠𒁯ꔠ𐙡啹院驳啳驨驲挮售𖠰筆筆鸠啳樶栵愵欠樵樳昫鸠啳樶栵嘶谠ꍥ啬𐙡𔕹𖥡唬驨驲鸠啳𒁹𓁵鬠陬潧㸍㸍ꍦ鱡汻欱靡驣洸鬰渰汢饣汣根騸饤杦样椶𠌸

Well, this the content of the file look like 😅😅

After seeing this text my first though

Me: Hey Google Translator, I have work for you convert the string into English

Google Translator:

Me: Hey ChatGPT, I have work for you convert the string into English

ChatGPT:

Solution Steps:

• File Download: Begin by downloading the provided file.
• Chinese String Observation: Upon inspection, the file appears to contain a Chinese string, adding an extra layer of complexity to the challenge.
• Deciphering the Hint: The challenge context provides a subtle clue “BASE FFFF+1.” Understanding hex values, FFFF translates to 65535. Adding 1 to this value yields 65536.
• Base65536 Decoding: Recognizing the significance of 65536, we deduce that the string is base65536 encoded. Decode this encoded string to reveal the hidden flag.

Conclusion:
In the “BASE FFFF+1” challenge, what initially seemed like a Chinese string takes on a new meaning through the lens of base65536 encoding. By deciphering the hint and decoding the encoded string, the elusive flag is unveiled, showcasing the challenge of thinking beyond traditional encoding methods.

LinkedIn Profile: https://www.linkedin.com/in/aashutosh-lodhi-0bb398179/

GitHub Repositories:
https://github.com/aashutoshlodhi/Huntress_CTF/tree/main/BaseFFFF%2B1