Converting .zip file into binary equivalent & embedding the same in Xml using C#

I am working on a project wherein i need to send a .zip file containing multiple folders and files over from server to client side using C#.
But the constraint is that i need to send it using XML string. For this i need to convert the .zip file into its binary equivalent and then embed the same in the xml.
So can anyone please help me with the conversion of the file to binary and embedding it i xml?
Help would be really appreciated..!!!
Thanks in advance!!!