AES-256 Encryption Explained
What is AES?
The Advanced Encryption Standard (AES) is an encryption method established by the U.S. National Institute of Standards and Technology (NIST) in 2001 as an official standard. It is used worldwide by governments, banks, and companies to protect sensitive data.
The number "256" refers to the key length in bits. The longer the key, the more secure the encryption. AES-256 uses a 256-bit key – that's 2256 possible combinations.
How Secure Is It?
To understand the scale: 2256 is a number with 78 digits. Even if you used every star in the known universe (approx. 1024) as a supercomputer testing billions of keys per second, it would take longer than the age of the universe to try all combinations.
That's why AES-256 is considered unbreakable – not for legal reasons, but for physical ones.
From Password to Key
You might enter a password with 8 characters – but AES-256 needs a key with exactly 256 bits (32 bytes). How does "Summer24" become a 256-bit key?
This is where a Key Derivation Function comes into play. It takes your password and generates a key of the required length through repeated mathematical calculations.
Protection Against Brute-Force Attacks
The key derivation function does something else important: it's intentionally slow. It runs your password through complex calculations thousands of times.
For you as a legitimate user, this makes no difference – a one-second wait when opening doesn't matter. For an attacker trying millions of passwords, it makes the attack significantly more difficult.
How Does Encryption Work?
Think of your data like a letter. Encryption translates this letter into a secret code that can only be read with the right key.
AES uses a symmetric method: the same key is used for both encrypting and decrypting.
What Happens to Your Data?
Your data is divided into many small pieces. Each piece is then run through a complex mathematical process that completely scrambles the data.
The result looks like complete chaos – without the right key, it's impossible to reconstruct the original data.
Security in the Cloud
A major advantage of local AES encryption: when you store your encrypted files in the cloud, they remain absolutely secure there too. The cloud provider only sees unreadable data.
This enables a form of end-to-end encryption when exchanging data between your own devices. Even in the event of a data breach at the cloud provider, your data remains protected.
Application in GrandTotal
GrandTotal uses AES-256 for encrypted company files. Your invoices, estimates, and customer data are encrypted locally on your Mac before being saved.
You can store the encryption password in the macOS Keychain, so you don't have to enter it every time you open a file – yet the files remain securely protected.
At a Glance
Global Standard
Used by governments and banks since 2001
Extremely Secure
Practically unbreakable, even with supercomputers
One Password Suffices
Same key for encryption and decryption
Password Quality Crucial
Weak passwords remain weak
Cloud-Safe
Encrypted files stay protected in the cloud