Updated Feb 2026 • 6 min read
You’ve encrypted your PDF. Excellent. But if the password you chose is "Password123" or your pet's name, you might as well have left the door wide open. In the world of cryptography, the encryption algorithm is the lock, but the password is the key. If the key is made of cardboard, the strongest lock in the world won't save you.
Modern computers can guess billions of passwords per second. So, how do you create a password that is memorable for you but impossible for a machine to guess? You go old school.
For years, IT departments told us to make passwords like this: Tr0ub4dor&3. It looks hard, right? It has numbers, symbols, and weird capitalization.
The problem is that it’s hard for humans to remember, but easy for computers to guess. Computers know that humans swap "o" for "0" and "a" for "@".
The "Old School" way, often called Diceware, relies on randomness and length. A long string of random words is mathematically harder to crack than a short string of complex gibberish.
1. Grab a standard 6-sided die.
2. Roll it 5 times to get a 5-digit number (e.g., 4-1-6-2-3).
3. Look up that number in a "Diceware Word List" (easily found online). Let's say it corresponds to the word "Horse".
4. Repeat this process 4 or 5 times.
You end up with a password like:
correct-horse-battery-staple
This password is 25+ characters long. Brute-forcing this would take a supercomputer millions of years, yet you can remember it by visualizing a horse holding a battery and a staple.
Every character you add to your password exponentially increases the difficulty of cracking it.
If the Dice method sounds like too much work, simply use a Password Manager (like Bitwarden or 1Password). These tools generate random garbage like 8#xK9!mP2$Lq and remember it for you.
However, for a PDF you are sending to someone else (like a mortgage broker), you can't use random garbage because they need to type it in. In these cases, the Random Word Method is your best friend. It allows you to call them and say "The password is purple-flying-elephant".
NEVER. If you reuse passwords, a hacker who cracks your Netflix account suddenly has access to your tax returns, your PDFs, and your email. Unique passwords for everything is the golden rule.