Crossed Wires

We are given N, e, d of the sender and N, e of his friends. The flag is encrypted using the friend’s public keys e1, e2, ..., e5 under the same modulo N. As seen in this link, we can factorise N given e, d using the given algorithm. From that, decrypting the plaintext should be trivial. Sage Implementation (slight modification and this can work on Python too) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 from Crypto....

December 12, 2022 · 2 min · qvinhprolol