A lot of the web is moving to HTTPS, which to my understanding does two things: Making the data unreadable by third parties, and verifying it's coming from the expected sender. The latter seems unarguably good, but the first also has some downsides.
The noticeable downside I see is that it completely disables any more centralized caching (the browser itself could still cache). I am wondering if it would be possible to have HTTP traffic that is signed, so that no MitM could alter the data, but not encrypt it so that parties like CDN, the ISP or just the local network admin could configure it to be cached and significantly speed up the requests, and also decrease load on the origin servers.
I can see this is not for every application applicable, but for more static and insensitive data like for example Debian ISO download, Wikipedia or jQuery library files this could be used.
Would signed but unencrypted HTTP be possible? Is there a real use for this or am I missing something?