1 min read
UTCTF - bits and pieces
author    -> Jozef Steinhübl
category -> cryptography
points    -> 467
solves    -> 218

Introduction

task

This task is extremely similar to the rsa-256 task, but with a multiple values of N, e, and c in a file vals.txt.

Explanatory notes
(N, e) is the public key
c is the ciphertext

Solving

We can solve this in the same way as the previous task, but we’ll do it three times.

bits and pieces first bits and pieces second bits and pieces third

Then just combine the results:

utflag{oh_no_it_didnt_work_</3_i_guess_i_can_just_use_standard_libraries_in_the_future}