project / 08Offensive security basics

SHA-1 Password Cracker

A Python dictionary attack against SHA-1 hashes, built to show how the attack works.

View source updated Feb 2026

Stack: Python
hashlib

Overview

Reads a wordlist line by line, hashes each candidate with SHA-1 and compares it to the target hash, stopping at the first match. Built for learning purposes.

Key features

Normalises the input hash (trim, lowercase)
Streams the wordlist rather than loading it into memory
Stops on the first match

Security concepts

Dictionary attacks
Password hashing (SHA-1)

Screenshots

Terminal output: one SHA-1 hash cracked to the password 'rohit', a second hash not found in the wordlist. — Two runs: one hash found in the wordlist, one not.

Notes

Educational use only.