PoW-server

Requirements:

Design and implement “Word of Wisdom” tcp server.
* TCP server should be protected from DDOS attacks with the Proof of Work (https://en.wikipedia.org/wiki/Proof_of_work),
the challenge-response protocol should be used.
* The choice of the POW algorithm should be explained.
* After Proof Of Work verification, server should send one of the quotes from “word of wisdom” book or any other
collection of the quotes.
* Docker file should be provided both for the server and for the client that solves the POW challenge

Server:

1. Incoming requests limited by MAX_CONNECTIONS env
2. Connection time limited by SESSION_TTL_SEC env
3. Metrics server available

Client:

1. Client pkg extracted
2. Reply policy available if server temporary unavailable (backoff algo)

PoW

• Challenge-response protocol implemented based on SCRYPT hashing algorithm.
• SCRYPT, compared to SHA-256 and Hashcash, is more ASIC-resistant due to memory-hard structure
  • you can increase memory consumption by increasing Scrypt params

Commands:

Dev

make lint 
make test
make local_run_server
make local_run_client

1. Start server

make build_server
make start_server

2. Start client

make build_client
make start_client