Base64

Description

Another common encoding scheme is Base64, which allows us to represent binary data as an ASCII string using an alphabet of 64 characters. One character of a Base64 string encodes 6 binary digits (bits), and so 4 characters of Base64 encode three 8-bit bytes. Base64 is most commonly used online, so binary data such as images can be easily included into HTML or CSS files. Take the below hex string, decode it into bytes and then encode it into Base64. 72bca9b68fc16ac7beeb8f849dca1d8a783e8acf9679bf9269f7bf 💡 In Python, after importing the base64 module with import base64, you can use the base64.b64encode() function. Remember to decode the hex first as the challenge description states.

2^6

As outlined in the description, we can decode the hex string into bytes and then encode it with Base64

import base64

HEX = "72bca9b68fc16ac7beeb8f849dca1d8a783e8acf9679bf9269f7bf"

# Decode the hex into a byte string
byteString = bytes.fromhex(HEX)

# Encode the byte string with base64
b64Flag = base64.b64encode(byteString)

print(b64Flag) # This flag has a slightly different format

Important thing I learned: Do NOT call your Python file "base64.py" because it overrides the standard library module base64 which causes a bunch of errors :(

Flag

crypto/Base+64+Encoding+is+Web+Safe/