How can I password protect winzip file on Windows PC?

When you password protect a ZIP file, the level of security depends not just on the password itself, but also on the encryption algorithm used for password protecting the winzip file. ZIP file formats support different encryption standards, each with varying strengths. Older ZIP utilities often rely on ZipCrypto, a legacy encryption method that provides basic protection but is considered insecure by today’s standards. Modern tools support AES (Advanced Encryption Standard), especially AES-256, which offers strong, military-grade encryption. Understanding these algorithms is key to choosing the right method for protecting your compressed files from unauthorized access.

ZipCrypto is a legacy encryption method originally introduced in the early versions of the ZIP file format. It offers basic password protection but has several known security flaws:

• Weak encryption: Uses a 96-bit key but lacks modern cryptographic standards.
• Easily cracked: Vulnerable to known-plaintext and brute-force attacks using readily available tools.
• Wide compatibility: Almost all ZIP utilities can open ZipCrypto-encrypted archives, which is its only major benefit.

Because of its weaknesses, ZipCrypto is not recommended for protecting sensitive data.

AES-256 (Advanced Encryption Standard with 256-bit key) is a strong, modern encryption algorithm adopted by governments and security agencies worldwide in order to password protect a winzip file:

• Strong protection: Offers 256-bit key length, making brute-force attacks computationally infeasible.
• Industry-standard: Used in secure communications, file encryption, and password management tools.
• Supported in ZIP files: Modern compression tools like 7-Zip and WinRAR allow users to create AES-encrypted ZIP or 7Z archives.

However, AES-encrypted ZIP files may not be compatible with older or default archive extractors like Windows File Explorer, which only supports ZipCrypto.