What if time travel targeting is based on electromagnetic effects of high-frequency processing and Bitcoin is how they sync the transmitters.
It's been speculated by several experts that Bitcoin was designed by a team of cryptographers, not some lone genius. For what purpose?
We can't find the creators of Bitcoin because they haven't been born yet. So, it's 2300 and time travel is discovered based on electromagnetic quantum effects.
They scan subspace and find an under-sea fiber repeater This repeater exists in 2009; its shielding was damaged and signal amplified by makeshift undersea tapping by a US submarine for the NSA. So they can interact with the Internet in 2009. But this transmitter isn't strong enough to target for transmuting physical matter. Too weak You can't timejump with just one transmitter on the ground because you have no idea if you're jumping into rock, blowing the planet open. They need beacons built, but they can only interact with us through the Internet.
These beacons would require incredible worldwide capital. So how do they make us continually transmit special, predictable electromagnetic signatures, synced generally worldwide, using a modem?
So they give us Bitcoin. And we create for them a worldwide web of nodes consuming megawatts of power to identify Earth in the timestream.

 swiftonsecurity