How to Encrypt a File Before Uploading It Anywhere

You don't need to trust a platform's security if you encrypt the file yourself before uploading. This gives you an additional layer of protection that travels with the file, regardless of where it's hosted.

Method 1: 7-Zip (Windows / Mac / Linux)

7-Zip is free and open-source. It can create AES-256 encrypted archives:

1. Right-click the file → 7-Zip → Add to archive
2. Set archive format to "zip" or "7z"
3. Check "Encryption" and choose AES-256
4. Enter a strong passphrase (use a password manager)
5. Click OK

Upload the resulting encrypted zip to TiniDrop or any other platform. Share the link and the passphrase separately — never in the same message.

Method 2: macOS Disk Utility (Encrypted DMG)

1. Open Disk Utility → File → New Image → Image from Folder
2. Select your file or folder
3. Set Encryption to AES-256
4. Enter and confirm a passphrase
5. Save the .dmg file

Method 3: GPG (All platforms, command line)

gpg --symmetric --cipher-algo AES256 yourfile.pdf

This creates yourfile.pdf.gpg. The recipient needs GPG installed to decrypt it with the same passphrase.

Method 4: Cryptomator (GUI, cross-platform)

Cryptomator creates an encrypted vault on your machine. Any file you put inside the vault is encrypted before it leaves. You can then upload the encrypted vault folder to any cloud storage.

Key Principle

Always send the passphrase through a different channel than the file link — SMS or voice call, not the same email thread where you shared the link.