# pip install cryptography
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives import hashes

private_key = ec.generate_private_key(ec.SECP256K1())
message = b"Pay 10 tokens to Asha"
signature = private_key.sign(message, ec.ECDSA(hashes.SHA256()))

public_key = private_key.public_key()
public_key.verify(signature, message, ec.ECDSA(hashes.SHA256()))   # raises if invalid
print("Signature valid: message came from the key holder and was not changed")

Why am I interested in blockchain?
☐ I enjoy cryptography and security
☐ I am interested in finance and payments
☐ I want to build new kinds of apps
☐ I want to specialise early
☐ I heard it pays well (verify this carefully!)
The first four are strong reasons to learn it deeply.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

contract Tips {
    mapping(address => uint256) public received;

    function tip(address to) external payable {
        require(msg.value > 0, "tip must be positive");
        require(to != address(0), "invalid recipient");
        received[to] += msg.value;
    }
}
// Learning exercise only: deploy on a testnet. Real contracts that
// move value need careful testing, withdrawal patterns and audits.

Skills that transfer beyond blockchain
Solidity testing habits      → software testing
Wallet + web integration     → full stack development
Cryptography basics          → cybersecurity
Ledger design thinking       → backend and data engineering
Building these keeps your options open if the blockchain job market shifts.

Red flags for students
✘ 'Guaranteed returns' or 'double your money'
✘ A job that asks you to pay or deposit crypto first
✘ Requests for your seed phrase or private key
✘ Pressure to decide quickly
✘ Unverifiable teams and anonymous promises
Rule: no legitimate employer or course needs your private key or real funds to teach you.

Balanced weekly plan (about 8 hours)
4 h: core programming (data structures, web or backend skills)
2 h: blockchain fundamentals and Solidity
1 h: security reading (common contract vulnerabilities)
1 h: project work on a testnet
Review every month: is blockchain still the focus I want?

Student blockchain path
1. Programming fundamentals (Python or JavaScript)
2. Web basics and APIs
3. Hashing, public-key cryptography, signatures
4. How blocks, consensus and transactions work
5. Solidity basics on a testnet
6. Testing contracts and common vulnerabilities
7. A small dApp project with a README

Student project ideas (testnet only)
- Event ticket contract with transfer rules
- Simple voting contract for a college club demo
- Certificate hash registry: store hashes of PDFs, verify authenticity
- Tip jar with a web front end
Each: tests, README, security notes

Monthly market check
Blockchain roles seen in job posts this month: ____
Common skills requested: ______________
General software roles seen: ____
Adjust plan? Yes / No — notes: ______