Q: Where Is the Password Of a Zip File Stored? How Does Zip Verify Correctness Of the Password?

No Zip archiver (nor any other program with data protection) saves or stores the password.

It is no use and is unsafe.

Every time you enter the password to open your encrypted archive, the archiver calculates the unique encryption key and uses this key to decrypt the Zip file.

If the entered password is correct, the archiver will calculate the correct key, decrypt the data, and you will get access to your file. If the entered password is wrong, you will be asked to enter the password again.

Fig. 1: Entering the correct and incorrect password to open a 7-Zip file

And that is the principle behind any password cracker – a password recovery program. They try all possible combinations of characters until they find correct password.

The best ones, such as Accent ZIP Password Recovery, offer range customization options and support acceleration on GPU to boost the speed of searching.

Fig. 2: Speed of brute force while cracking zip passwords using AccentZPR (passwords per second)

P.S. Speaking of Zip, one should note the great variety of algorithms that are in generating keys and file encryption. This may lead to confusion and errors while using archives.

More details and free demo:

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for classic Zip/WinZip AES encrypted archives
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