Behind the Scenes: How Hashing Protects Your Passwords

We dive into the world of cryptographic hash functions, explain the difference to encryption, and show you why techniques like 'salting' are indispensable today. Learn why a good system doesn't even need to know your password to know it's correct. This knowledge helps you understand why some security rules (like password length) are so important. Welcome to the engine room of cybersecurity.

The most important difference first: encryption is a two-way street. With the right key, you can restore the data to its original state. Hashing, however, is a one-way street. A hash function takes an input (your password) and calculates a fixed value (the hash) from it.

From this hash, the original input cannot be calculated mathematically anymore. When you log in, the website recalculates the hash of your input and compares it with the stored value in the database. If both match, the password was correct. The clou: the company itself never knows your password in plain text at any time. Even if the database is stolen, the thieves only have the hashes, with which they can do little without massive computing power.

Hackers are clever. They pre-calculate hashes for millions of common passwords (so-called rainbow tables). If two people use the same password, they have the same hash. If the hacker finds this hash in the list, they immediately know the password.

This is where 'salting' comes into play. A 'salt' is a random string of characters that is appended to your password before hashing. The result: even if two people have the same password, they generate completely different hashes through different salts. This makes the use of rainbow tables impossible. Every password must be cracked individually and with enormous effort. A good system generates a new, random salt for every password. It's a simple but extremely effective method to fend off mass attacks.

Normally we want computers to work as fast as possible. With hashing, the opposite is the case. Good hashing algorithms like Argon2 or bcrypt are intentionally designed 'slow'. They need a few milliseconds more computing time per process.

For a normal user, this delay is not noticeable. For a hacker who wants to test billions of combinations per second, however, it is an insurmountable hurdle. Every additional millisecond per test attempt sums up to centuries of computing time for billions of attempts. Time is the currency of security here. So if you use long passwords, you force the algorithms to peak performance that no attacker can economically handle. Cybersecurity is often a game against time.

When you hear about a 'leak' in the news where millions of passwords were stolen, it usually means that the database with the hashes was stolen. The danger for you now depends on how well the hashes were protected.

Were they salted and hashed with a modern algorithm? Then your data is relatively safe, provided your password was not extremely simple (like 'password123'). Hackers then use 'brute force': they simply try out passwords, hash them, and see if they match the stolen goods. That's why the length of your password is so crucial – it increases the number of possible combinations so much that a hit becomes statistically impossible. At SavePaper.work, we therefore always recommend the use of our password generator.

Understanding hashing shows you why certain behaviors are so important. Here are 3 lessons from the technology:

1. Password Length Is King: the longer the password, the more useless the hash is for a brute-force attack.
2. Uniqueness: if a hash is cracked, it should only apply to a single service.
3. Trust in Technology: use services that employ modern standards (like Argon2).
   
   Technical knowledge takes the fear out of the digital world and replaces it with competent action. We at SavePaper.work want to accompany you on this path and provide you with the tools you need for your security. Education is the best protection.