"I feel uncomfortable with crypto currencies, partly because I do not understand them ! and feel there has to be a great element of trust in the cloud or internet for this all to work."

I think your concern is valid in the sense that the network must be operational in order to support these currencies. However, the internet has become a utility on which virtually every organization, government and otherwise, presently depends. Furthermore, private and independent mesh networks are springing up all over. The present amount of capital dependent upon the operation of the internet is incredibly vast. Because of this, it is my belief that those who own that capital will stop at nothing to keep the network operational.

"I think this crypto currency phase could be hijacked by the rulers"

I don't believe that to be possible. While the powers that be will very likely develop and deploy their own versions of crypto, the distributed versions are already beyond their reach.

Without getting into an extremely long discussion, I'll summarize my thoughts about "the mark" you refer to.

I believe that some writers, for example Hal Lindsey and Tim LaHaye, have sensationalized the end times and produced an unrealistic caricature of what the bible actually teaches. The mark of the beast is a prime example.

Paul tells us that, as believers, we bear God's mark:

"In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory."
Ephesians 1:13-14

This is the seal spoken of in Revelation 7, there symbolically placed on the foreheads of God's people. It is the opposite of the mark of the beast. Just as a brand identifies cattle, the seal of the Holy Spirit identifies God's own, while the mark of the beast identifies Satan's own.

These things have no relationship to physical reality other than this: Those who are sealed by the Spirit, we who follow Jesus, will refuse to participate in dishonest and coercive systems. That is one of the primary reasons that we will have trouble in the world. We simply don't fit in.

The entire thesis of my article is that cryptocurrency is, if anything, an antidote, or counter to the beastly world system of coercion.

Thanks for participating in this discussion! :D