I would argue that, theoretically, proprietary can be secure. A code base can be made secure by highly experienced engineers who are paid to make the code secure. You might never be able to see the code, but it could still be secure. The problem is that you can never actual verify how secure the proprietary solution is. So whether or not it is secure, you don't trust it. (there are even some interesting arguments to be made about the security of any solution that deals with some kind of user input. my previous boss stipulated that the only way to have a truly secure email client is to have some third-party, verified library that takes all the input, and spits out encrypted data to whatever program deals with email servers, without the program dealing with email servers ever seeing that input in plain text form because who knows what it might do with it)
On the other hand as well, open source most certainly does not mean secure. I don't even have to argue to make this point, I merely have to point out Heartbleed or Shellshock.
On the other hand as well, open source most certainly does not mean secure. I don't even have to argue to make this point, I merely have to point out Heartbleed or Shellshock.