Every day, thousands of accounts are compromised because passwords are too simple or reused. Yet just a few straightforward rules are enough to create effective protection. Here’s how to design a strong password that’s hard to guess and suitable for all your accounts.
What you must never do
Common mistakes to avoid
A weak password is often:
- Too short
- Made up only of letters or only of numbers
- Based on personal information that’s easy to guess (first name, date of birth, town, etc.)
A password like “123456”, “azerty” or “motdepasse” can be cracked in a few seconds.
The principles of a strong password
A few essential rules
To be effective, a password must:
- Be at least 12 characters long
- Mix lowercase, uppercase, numbers and special characters
- Be completely unrelated to your identity
- Never be reused on several sites
If you use the same password for your email inbox, your social networks and your online banking, a single hacking incident compromises everything.
Simple tips for creating memorable passwords
Use a coded personal phrase
Make up a sentence whose meaning only you know, then transform it.
Example:
“Ma grand-mère m’appelait chaton en 2005 !”
➜ Mgmm@cE2005!
A very simple trick that generates a unique, strong password that’s easy to remember.
Replace letters with numbers and symbols
Known as Leet Speak, this system turns letters into look‑alike characters. It’s a very useful technique for increasing a word’s complexity.
| Letter | Possible representation |
| A | 4 or @ |
| E | 3 |
| S | $ or 5 |
| T | 7 |
| I | 1 or ! |
| O | 0 |
Illustration of the Leet Speak principle
A table of the most common matches used in secure typographic transformation.
And how not to forget them?
Choose a password manager
If you have dozens of accounts (which is the case for most internet users), it becomes hard to memorise every password. In that case, use a secure digital vault.
These encrypted tools allow you to:
- Generate complex passwords
- Store them safely
- Fill them in automatically in your forms
That way, you only have one password to remember: the one for the vault.
Summary of best practices
- Minimum length: 12 characters
- Mix of different types of characters
- No personal information
- A different password for each site
- Use coded phrases
- Use Leet Speak with a clear logic
- Change sensitive passwords regularly
- Use a manager if needed
