Introduction

Here the values of n, ct and e are given. Which likely states that it is an rsa encrytion.

Problem And Solution

Here we are not given the value of private key exponent(d). So it is not possible for us to decrypt it directly with a key.

But if you notice there is something odd with the value of e. The value of e is very small.After some research I found that

this is one of the simplest attacks on RSA which arises when m^e is less than n(Note:Here m is the message,e the exponent and n the modulus).

When this is the case, the modulo n loses it's significance and the encryption reduces to m^e (Note: normal encryption is (m^e)%n).

Thus ciphertext becomes m^e which implies m is the eth root of ciphertext(eg:2^4=16 implies 2 is the fourth root of 16).

Click Here for the code.

b'recr{flaggie}'