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How AES-256-GCM Encryption Works in Plain English?

· 4 min read
The LockYit Team
The LockYit Team
Security focussed. Privacy centric.

When we say LockYit uses "AES-256-GCM encryption", that can sound intimidating. But the idea behind it is surprisingly simple. Let's break it down in plain language - no computer science degree required.

Think of It Like a Lock and Key​

Imagine you have a safe with an incredibly complex lock. You put your valuables inside, turn the key, and now nobody can open it without that exact key. That is essentially what encryption does with your digital data.

When you create a vault item in LockYit - say, a password or a credit card number - the app scrambles that information into something completely unreadable before saving it. The only way to unscramble it is with the right key. That key is derived from your master password, which only you know.

What Does "AES-256" Mean?​

AES stands for Advanced Encryption Standard. It is the encryption method used by banks, governments, and militaries around the world to protect classified information. It is not something we invented - it is an internationally recognised standard that has been tested and trusted for over two decades.

The 256 refers to the size of the key used to lock your data. A 256-bit key means there are 2^256 possible combinations - a number so large that every computer on earth working together could not guess it before the end of the universe. In practical terms, it is unbreakable with current technology.

What Does "GCM" Add?​

GCM stands for Galois/Counter Mode. In simple terms, it adds a layer of tamper detection on top of the encryption.

Regular encryption scrambles your data so nobody can read it. GCM goes a step further - it also checks whether anyone has tried to modify the encrypted data. If someone were to alter even a single character of your encrypted vault file, GCM would detect it and refuse to decrypt. This means your data is not only private, but also verified to be exactly what you saved.

Think of it like a sealed envelope. The encryption hides the letter inside. GCM is the wax seal on the back - if the seal is broken, you know someone tampered with it.

How Does This Work in LockYit?​

When you unlock LockYit with your master password, here is what happens behind the scenes:

  1. Your master password is used to generate a unique encryption key. This key never leaves your device and is never sent anywhere.
  2. Every item in your vault is encrypted individually using this key with AES-256-GCM.
  3. When you view an item, LockYit decrypts it on the spot using the same key. The decrypted data exists only in memory while you are looking at it.
  4. If anything has been tampered with, the decryption fails entirely rather than showing you corrupted data.

Because all of this happens locally on your device, your unencrypted data is never exposed to the internet, to our servers, or to anyone else.

Why Should You Care?​

You do not need to understand the mathematics behind AES-256-GCM to benefit from it. What matters is this:

  • Your data is locked with the strongest widely-used encryption standard in the world.
  • Only your master password can unlock it - not us, not a hacker, not anyone.
  • If someone tampers with your data, the app will know and will not show you compromised information.
  • It all happens on your device - your private information never travels to a server where it could be intercepted.

When you use LockYit, AES-256-GCM is working quietly in the background every time you save, view, or edit an item. You do not need to configure anything or make any choices - the strongest available protection is always on by default.

Security should not require expertise. LockYit handles the complex cryptography so you can simply focus on keeping your life organised. If you would like to learn more about how LockYit keeps your data safe, see our post on what offline means in LockYit.