What is commonly used for Encryption over simple Socket Communications

Question

I have X interfaces to Y computers that communicate over a public network (Think colleges and libraries). I am researching common industry standard techniques for encrypting the data that goes between us.

I know there is SSL, but I'd rather find a simple technique that is a "purchase once, install infinite" (trying to keep my variable costs down). I've thought about OpenSSL with Indy Sockets, but want to keep my mind open for other techniques.

I want to find a solution I can pitch to the Vendors I am communicating with. This solution needs to be cheap to buy, install and secure.

What's out there? What's being used? How hard is it to implement these solutions in code? What are people currently using to encrypt simple Socket to Socket communication?

Edit: I currently use RAD Studio 2009. However, my vendors can use anything from Java, VS2008 to others like 4D. Whatever I find I need to be able to pitch to everybody. I would like the entire stream encrypted. But, I am worried that some older technologies that my vendors use may not be able to use SSL. I'm also posting this to make sure I'm not missing anything obvious (like The Microsoft Message Queue)

Answer 1

It seems like you already answered yourself with OpenSSL.

What platform are you coding for? What language are you using? Do you want to encrypt the entire stream? Or just certain pieces of data?

It sounds like you're looking for something that is just a lot easier to use 'out of the box' than OpenSSL, no?