Radix64

Platform: spbctf | Category: Crypto | Type: Challenge | Difficulty: Easy | OS: NA | Author: XESXOR | Date: 2026-03-08 | Status: Solved Techniques: Character translation between alphabets, crypt(3) radix64 decoding, Identify non-standard base64 alphabet

Summary

Task: Decode radix64 encoded data using crypt(3) alphabet. Solution: Translate from crypt(3) alphabet to standard base64 alphabet, then base64 decode.

Radix64 — cryptokids20

Description

Radix64 with crypt(3) alphabet: ./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz

Solution

Translate from crypt(3) alphabet to standard base64 alphabet, then base64 decode. ‍​‌‌​​‌​​​‌‌​​‌​​​​‌‌​‌​​​​‌‌‌​​‌​​‌‌​​​‌​​‌‌‌​​​​​‌‌​‌‌​​​‌‌​​​​‍