Since he brought to light the enormous spying efforts of the US government two years ago, Edward Snowden has opened our eyes to a slew of related and (sometimes, not so related) topics. Some are not quite expected, though, such as one he revealed during a chat with Neil deGrasse Tyson on his StarTalk podcast. Essentially, encryption could harm our chances of making contact with aliens. E.T. phone home? Not easily done with encryption.
During the chat, Snowden says that if encryption is implemented really well, then it wouldn't be recognizable as encryption at all. Instead, it'd simply be random noise. Because of that, if aliens managed to pick up a signal, it could simply be chalked up as randomness, "indistinguishable to us from cosmic microwave background radiation", he says.
That's obviously a big issue if we ever want to make contact with potential alien civilizations that are out there. Snowden says that it's likely any civilization will only have open communications for some time; afterwards, evolution will apparently end up introducing encryption.
It's interesting to hear Snowden talk about this potential downside of encryption, as his 2013 revelations have proven that encryption is actually much more important than ever. Clearly, though, this is a bit of a special case, and it's hard to imagine that this alone would prevent two civilizations from making contact - not all communication is encrypted, after all. Nonetheless, it's definitely something interesting - and perhaps fun - to think about.