The Encrypt Dialog

The Encrypt dialog allows you to specify a password and encryption method when encrypting files. The dialog is displayed

when files are being added to an archive and you have checked the Encrypt added files check box in the Add dialog, or
when you choose Encrypt from the Actions menu or from the WinZip® shortcut menu in Windows Explorer. Note that this action encrypts or re-encrypts all files in the Zip file. Please see About Encryption for more information about this action.

To begin encrypting files:

Type the desired password in the Enter password edit field (read about passwords in the "Notes on using encryption" section).
Tip: check the Mask password check box to prevent the password from being displayed as you type it. If you check this option, the dialog will require you to type the password twice for confirmation (to avoid typographical errors in the password).
Click the desired encryption method in the Encryption method area. (Note: this option appears for Zip files only.)
Click OK to begin the action you requested.