Like the other posts imply, it sounds like something else is going wrong. Is DCC actually processing files during the long time period or are you just waiting indefinitely for images to get OCRed?

For anyone who is curious, here is how you would find password protected PDFs using the sdk. Download the electronic file and use iTextSharp to open it. Not shown is the code to run a search for {LF:Name="*", Type="D"} that finds all documents in the repository.

bool isPasswordProtected(DocumentInfo doc)
{
    string contentType;
    using (MemoryStream pdfStream = new MemoryStream())
    using (LaserficheReadStream edocStream = doc.ReadEdoc(out contentType))
    {
        edocStream.CopyTo(pdfStream);
        pdfStream.Seek(0, SeekOrigin.Begin);

        try
        {
            PdfReader reader = new PdfReader(pdfStream);
            return false;
        }
        catch (BadPasswordException)
        {
            return true;
        }
    }
}