Tap The Wire

Description

Ronald and Rivest wanted to exchange information. They agreed to use Diffie Hellman key exchange using p and g. They picked random numbers Ronald = 7 and Rivest = 3. The message is encrypted using the key generated, Can you decode the message?

Hint: I heard from a little birdie , Ron likes to code

message.txt

Solution

• The message is encrypted using the key generated by Diffie Hellman key exchange.

• Using dcode.fr we can compute the key using the given values of p, g, Ronald and Rivest

6840299821867275125726358685299896195672229203188775332403304336456358299900402885839216477521129304756783706116014993809561111708253794750569703800517890029

• Convert to hexadecimal using this

1FE2C410F971C97F0230FFC70E009661602850EC3FFCA6BA973C1FE021AD2A637DFF2CDD21821C285246540948072A64CE62961B8AFE6028012D2B63974F1470FED

• RC2 decrypt using the hexadecimal as key, we get the flag.

FLAG

pesu_ec{n0_m0r3_man_in_middl3}