Yes but some points have priorities: -- "Every exchange will leave a full track - where, when, what" already should raise a "you'd better be joking". -- Fails

Yes but some points have priorities: -- "Every exchange will leave a full track - where, when, what" already should raise a "you'd better be joking". -- Failsafe fallback: a system depending on running infrastructure (electricity, internet, servers etc.) is badly conceived.