Key Exchange using AES and Crystal-Kyber

This repo demonstrates key exchange mechanisms using AES and Crystal-Kyber algorithms. The setup involves two clients and one server for both key exchange methods.

Prerequisites

• Node.js installed on your machine
• openssl installed for generating RSA keys

AES Key Exchange

1. Client A generates a shared AES key.
2. Client A encrypts the AES key using the server's public RSA key.
3. Client A sends the encrypted AES key to the server.
4. Server decrypts the AES key using its private RSA key.
5. Server encrypts the AES key using Client B's public RSA key.
6. Server sends the encrypted AES key to Client B.
7. Client B decrypts the AES key using its private RSA key.

Crystal-Kyber Key Exchange

1. Client A generates a Crystal-Kyber public-private key pair and a shared symmetric key.
2. Client A encrypts the shared symmetric key using the server's Crystal-Kyber public key.
3. Client A sends the encrypted symmetric key to the server.
4. Server decrypts the symmetric key using its private Crystal-Kyber key.
5. Server encrypts the symmetric key using Client B's Crystal-Kyber public key.
6. Server sends the encrypted symmetric key to Client B.
7. Client B decrypts the symmetric key using its private Crystal-Kyber key.

Project Structure

.
├── server
│ ├── server.js
│ ├── server_private.pem
│ ├── server_public.pem
│ └── .env
├── client_A
│ ├── server.js
│ ├── client_a_private.pem
│ ├── client_a_public.pem
│ ├── shared_secret.pem
│ └── .env
└── client_B
├── server.js
├── client_b_private.pem
├── client_b_public.pem
└── shared_secret.pem

Installation

1. Clone the repository
2. Navigate to each directory (server, client_A, client_B) and install dependencies:

cd server
npm install

cd ../client_A
npm install

cd ../client_B
npm install

Key Generation

Generate RSA key pairs for the server and clients:

# Generate RSA key pair for the server
openssl genrsa -out server/server_private.pem 2048
openssl rsa -in server/server_private.pem -outform PEM -pubout -out server/server_public.pem

# Generate RSA key pair for Client A
openssl genrsa -out client_A/client_a_private.pem 2048
openssl rsa -in client_A/client_a_private.pem -outform PEM -pubout -out client_A/client_a_public.pem

# Generate RSA key pair for Client B
openssl genrsa -out client_B/client_b_private.pem 2048
openssl rsa -in client_B/client_b_private.pem -outform PEM -pubout -out client_B/client_b_public.pem

Running the Project

1. Start the server:

cd server
npm run dev

2. Start Client A:

cd ../client_A
npm run dev

3. Start Client B:

cd ../client_B
npm run dev

Measuring Key Exchange Time

The server logs the time taken to perform the key exchange in milliseconds for both AES and Crystal-Kyber key exchanges.