@KranthiAnnavarapu The following code checks if a pdf is password protected. Declare encrypted  as a boolean property.

Source: https://stackoverflow.com/questions/15896691/how-to-check-if-a-pdf-is-password-protected-or-not

ClipboardProperty filePathRef = tools.getProperty("pxRequestor.pyFileUpload");
String filePath = filePathRef.getStringValue();
PRFile dataFile = new PRFile(filePath);
encrypted = false;
    try {
        org.apache.pdfbox.pdmodel.PDDocument doc = org.apache.pdfbox.pdmodel.PDDocument.load(new PRInputStream(dataFile));
        if(doc.isEncrypted())
            encrypted=true;
        doc.close();
    }
    catch(Exception e) {
        encrypted = true;
    }