It adds complexity, but it ultimately isn't really particularly difficult.
The problem is that your backend servers can no longer operate on that data in any meaningful way. For this reason, full end-to-end encryption is likely not realistic for certain applications.
Simpler applications, like iMessage, can and do implement end-to-end encryption without much difficulty at all.
The problem is that your backend servers can no longer operate on that data in any meaningful way. For this reason, full end-to-end encryption is likely not realistic for certain applications.
Simpler applications, like iMessage, can and do implement end-to-end encryption without much difficulty at all.