Kim Dotcom to open his own encrypted e-mail service

"The biggest tech hurdle is providing email functionality that people expect, such as searching emails, that are trivial to provide if emails are stored in plain text (or available in plain text) on the server side," Kumar said. "If all the server can see is encrypted text, as is the case with true end-to-end encryption, then all the functionality has to be built client side. [That's] not quite impossible, but very, very hard. That's why even Silent Circle didn't go there."

Thus, Kumar warned a service from Mega may take some time. "[It's] exciting stuff, but very hard, so I think it will take months more to crack it. But Mega will never launch anything that undermines its end-to-end encryption core security proposition and doesn't work for the mythical grandmother."