How to password protect a zip file in Windows 11?

Windows 11 built-in ZIP compression tools and most ZIP encryption tools support the following two encryption methods. You can use one of them to password protect a zip folder on Windows 11. Below are the details for the two encryption algorithms.

ZipCrypto (traditional encryption)

Algorithm: Symmetric encryption (old standard before AES became popular).

Security: weak, vulnerable to known plaintext attacks (e.g. using WinRAR, 7-Zip, etc. to try to crack).

Scenarios: High compatibility, suitable for older systems or simple encryption needs.

AES-256 (recommended)

Algorithm: Advanced Encryption Standard (256-bit key).

Security: Currently the most secure ZIP encryption method, with strong resistance to brute-force cracking.

Scenario: Supported by Windows 11 built-in ZIP tool, 7-Zip, WinRAR, etc. It is recommended to prioritize the use.

Note: Windows 11 built-in ZIP encryption uses AES-256 by default, but filenames are not encrypted (you need to check “Encrypt filenames” with 7-Zip to enhance security).

2. ZIP encryption precautions
✅ Security Recommendations

Use a strong password: at least 12 digits with upper and lower case letters, numbers, symbols (e.g. P@ssw0rd!2024).

Prefer AES-256: avoid ZipCrypto (easy to crack) to password protect a zip file.

Encrypt filenames (if you need to hide them): with 7-Zip check -mhe=on (not supported by Windows built-in tools).

❌ Common Errors

Forgot password after encryption → ZIP has no official way to retrieve it, make sure to keep it safe!

Only compressed but not encrypted → You need to click the “Encrypt” button manually, otherwise the file is not protected.

File name reveals information → File name is not encrypted by default (if sensitive, use 7-Zip instead).