Safe RSA

Safe RSA

Points: 250

Category

Cryptography

Question

Now that you know about RSA can you help us decrypt this ciphertext? We don't have the decryption key but something about those values looks funky..

Hint

RSA tutorial

Hmmm that e value looks kinda small right?

These are some really big numbers.. Make sure you're using functions that don't lose any precision!

Solution

Since n is really huge and e is really tiny, we can figure out the message without needing to factorise n!

We can assume that m ** e < n. Therefore we do a cube root on c, and convert the value into ascii.

Working solution solve.py

Flag

picoCTF{e_w4y_t00_sm411_81b6559f}