I remember a PAR presentation online (maybe Autrijus') in which he suggests putting one critical module on a remote server. However in addition to liability resting on your neck now, it isn't secure and can be read by the user or admin if they really wanted to read it. What is your security need? Do you mean "can't be stolen and resold", "they have to pay", "has to be liscensed per user", "Don't want them to see my dirty code", "want to encrypt server traffic", "want to protect passwords and credit card numbers", or what? If the person running the server is your enemy, the answer is no. But you can do some secure things in perl i.e. regarding webapps.