At least one lowercase character - when this option is checked, a valid password needs to contain at least one lowercase character, a through z.See Encryption Passwords for more information on the use of passwords. Password must containīy setting a password policy, you can configure WinZip to disallow encrypting files with a password that does not meet the strength requirements defined by the policy. This tab allows you to configure both aspects of encryption. The security of your data depends not only on the strength of the encryption method but also on the strength of your password, including factors such as length and composition of the password. Select the Encryption tab in WinZip Settings to configure WinZip's ® password policy and default encryption method.