Audit ZIP archives for password protection, identify ZipCrypto vs AES-256 encryption algorithms, and safely test credentials 100% locally in your browser.
Drop or select any .zip archive to inspect its binary header encryption flags.
Review the automated diagnostic determining if the ZIP is locked with ZipCrypto or AES-256.
If encrypted, enter your candidate password into the local verification panel to test if it unlocks the contents.
Both bit flag header auditing and password trial decryption are performed locally in browser memory without sending credentials to remote servers.
Distinguishes standard legacy ZipCrypto protection from modern AES-256 bit extra header encryption structures.
Test your remembered passwords safely against the archive structure without locking out or modifying the original file.
Detecting Zip Encryption Flags & Header Signatures: Determining whether a zip archive is password-protected requires inspecting General Purpose Bit Flags in Local File Headers. Bit 0 being set (0x0001) indicates that files are encrypted, while extra fields signal advanced encryption standards (e.g. AES-256 WinZip AES header 0x9901).
ZipCrypto vs. AES-128 / AES-256 Encryption Security: Legacy ZipCrypto encryption is vulnerable to known-plaintext attacks due to weak cipher design. Modern archives use AES-256 encryption with PBKDF2 key derivation (1000+ iterations), providing robust protection against unauthorized data extraction.
100% In-Browser Encryption Verification: Password testing and encryption checking run 100% locally in web browser RAM using WebAssembly crypto libraries. Password entries, encryption keys, and archive payloads are never transmitted to cloud servers.