Sure crypto relies on electricity somewhat, but imagine a scenario where the electricity is cut. I doubt your first worry is your money or anyone elses for that matter. But there's also projects working on broadcasting the blockchain from space with cube satellites (http://nexusearth.com NXS, Nexus coin). Here's a little "humoristic" response to these SHTF scenarios from TVD It doesn't get very technical there, but trust me, everyone asks these same questions when they are getting in, and yes they have been thought out, even if they might not seem that obvious.... Text not showing up thats why this 2nd comment... @.@