Covenants in Elements Alphahttps://blockstream.com/2016/11/02/covenants-in-elements-alpha.htmlτην ιδέα των vault και των οικονομικών συμφωνιών την είχε παρουσιάσει ο Emin στο συνέδριο scalling bitcoin. H ιδέα είναι ότι τα bitcoin μπαίνουν σε ένα vault όπου μπορεί κάποιος να τα ξοδέψει όταν κατέχει το cold και το hot key και αφού περάσει κάποιο χρονικό διάστημα από την ώρα την εντολής συναλλαγής. Με αυτό τον τρόπο αν κάποιος έχει κλέψει το hot key ο κάτοχος του cold key έχει τον χρόνο να δει ότι η συναλλαγή έχει γίνει boradcasting στο δίκτυο και μπορεί να την στείλει σε κάποια άλλη διεύθυνση. Φυσικά το ίδιο μπορεί μετά να κάνει και ο attacker βάζοντας σε ένα loop τα bitcoin μέχρι κάποιος να βαρεθεί και να κάνει πίσω
Funds locked by a Moeser-Eyal-Sirer vault are accessible by one of two keys: a hot key, intended to reside on-line, and a cold key that is intended to be kept safely off-line and only used for recovery purposes. Under normal circumstances, the hot key is used to create a transaction that spends coins from the vault, but whether the hot key or the cold key is used, funds spent from the vault must first pass through a time lock that holds the funds for some fixed period of time, for example, 24 hours. The idea being that if a malicious party gets hold of the hot key, they must publicly broadcast this time-locked transaction on the blockchain before they can take ownership of the funds. This gives the vault owner 24-hours to detect that their funds are being moved by a malicious party and recover those funds. This is where the cold key come in.
During the 24-hour time lock period, the script allows the funds to be redirected to another address using the cold key. However, even when the cold key is used to redirect the funds, that transaction must pass through another 24 hour time lock. The cold key can be used to redirect the funds again during this second time lock, and so on. The idea here is that even if the malicious party gets hold of the cold key, they still cannot get access to the funds. The owner and the malicious party can continue to use the cold key to redirect the time locked funds back and forth between addresses. As long as they both remain active the funds will remain caught in this vault loop indefinitely.
A Moeser-Eyal-Sirer vault is composed of two scripts. The first script is the main vault script that locks the funds with the hot and cold keys. The second script contains the 24-hour time lock which allows the cold key to be used to redirect the funds. Because this second script can redirect the funds back to the same 24-hour time locked script, we call this the script the vault loop script.
ωραία ιδέα που αν αναπτυχθεί νομίζω θα έχει μέλλον στην μεγαλύτερη ασφάλεια των bitcoin σε κάποιο πορτοφόλι.