Skip to content

Latest commit

 

History

History

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
 
 
 
 
 
 
 
 
 
 

README.md

Secure Channel

by prajnapras19


Flag

COMPFEST13{4fd29464a28a1b39559f4fc500b41c4b17ec8ad74512394a830b51506AIUEOuh_f8facf99fe}

Description

You are able to watch the encrypted chat of Alice and Bob. They are talking about the flag right now. Can you get the flag from them?
P.S.: Alice and Bob once have said that they will communicate with some trivial encoding, so people will not notice their message at first glance. Although, people will know it if they search it on the internet! Sure, all of it is printable characters.
Watch the conversation: nc <HOST> <PORT>
Talk with Alice: nc <HOST> <PORT>
Talk with Bob: nc <HOST> <PORT>

Difficulty

Easy-medium

Hints

  • My trusted source said Bob's key is too low. And they use the same key everytime.

Tags

Cryptography, CRT, modular maths, Diffie-Hellman key exchange

Deployment

  • Install docker engine>=19.03.12 and docker-compose>=1.26.2.
  • Run the container using:
    docker-compose up --build --detach
    

Notes

  • There are 3 services: to watch the conversation, to talk to Alice, to talk to Bob.
  • Expected connections to services ~100.