by flying_whale on 9/21/15, 10:29 AM with 85 comments
by Mithaldu on 9/21/15, 11:31 AM
Encryption is applied on the data layers not to hide that something is being transmitted, but what is being transmitted.
However scientists aren't even trying to detect signals with any sort of data in it, but merely radio emissions that look like they might come from something with an intellect.
If we haven't found anything like that yet, and encryption is supposed to be the reason, then that means that encryption would have to be applied at the most basic protocol layer in such a way that even the physical properties of the emission look like the universe's background radiation. Is there currently human technology that does anything similar to this?
by bhaak on 9/21/15, 11:16 AM
But it doesn't even need to be encrypted communication. Highly compressed communication is also indistinguishable from random noise.
Of course, only under the assumption, that aliens are using the same technology as we are.
by d_theorist on 9/21/15, 4:22 PM
What actually is the point of communicating at sub-luminal speed between star systems or galaxies, other than CETI projects? The delay between transmissions would make such communication impractical for day-to-day purposes.
Perhaps this is one possible explanation for the apparent lack of such signals. Either the aliens don't bother much with communicating at galactic scales, or they have developed a system of doing so at super-luminal speeds that eludes our current understanding of physics.
If this is correct then you would expect most artificial radio signals to be easy to detect and decipher, because the only plausible use for such signals is long-term communication with alien civilisations. And you might also not expect to find many of them.
by nabla9 on 9/21/15, 11:50 AM
Turbo Codes and LDPCs used to transmit data over noisy channels (like NASA uses in deep space satellite communications or UMTS and LTE networks) look just like noise. I don't think Seti or astronomers have ever tried to analyze noise for some alien codec that might be transmitting.
by radmuzom on 9/21/15, 11:27 AM
Or perhaps this was just some light-hearted conversation which has been reported as "news" because Snowden was involved. I can as well say that we have not yet heard from the aliens because we are yet to discover the Mass Relays and the Citadel (apologies to those who have not played the Mass Effect series of video games and this statement makes no sense).
by tired_man on 9/21/15, 12:43 PM
It's more likely that we and the aliens wouldn't be using the same technology.
by nbush on 9/21/15, 12:02 PM
1. https://en.m.wikipedia.org/wiki/His_Master%27s_Voice_(novel)
by SagelyGuru on 9/21/15, 10:56 AM
by Tepix on 9/21/15, 11:41 AM
That and our limited brain capacity, which prevents us from recognizing and/or understanding a message from an advanced alien civilization.
by morsch on 9/21/15, 11:29 AM
If all communication itself on Earth were encrypted, how much of a visible signal would we still emit? You wouldn't be able to decypher the communication, but you'd still see that something is happening that's requires a structuring intelligence behind it. Unless they pay special attention to not only encrypting their communication but masking it as a natural phenomenon, steganographically.
If I shout an encoded message to you in a restaurant, the other people won't know that I told you to order the creme brulee, but they will know that I told you something. I'd have to discreetly tap my plate in order to mask it.
And even aside from that, you'd need to mask all other emissions, even those not designed to facilitate communication. On earth, you don't have to intercept and decrypt a rocket launch command, you can tell by the infrared (or whatever) emissions on your spy satellite.
by mcguire on 9/21/15, 6:10 PM
To my eternal regret, I didn't call him on the fact that those two blocks are not arbitrarily composable.
Both encryption and compression make the resulting data look random (and you can't compress encrypted data), and compression seems to be a much more likely candidate.
P.S. And spread-spectrum transmissions, as someone else mentioned.
by d_theorist on 9/21/15, 2:58 PM
by jgrahamc on 9/21/15, 11:27 AM
by current_call on 9/21/15, 2:57 PM