We can think of the CL as principally focused on enforcing property rights.

Conceptually this is clear, assets can only be transferred with the permission of it’s owner. This is the main invariant we want the CL to enforce.

So what do we mean when we say that an asset is moved from CL to a Zone, Zone to Cl, or between Zones?

First let’s set some ground rules:

• an “asset” is always owned by an entity.
• an “asset” can be transferred between entities only if the current owner approves of the transfer.
• an “asset” is represented as a commitment on chain.
• ownership of this asset is void when the nullifier of an asset is added to the chain through a valid transaction (it’s not enough to simply know the nullifier of a commitment in order to void a commitment)

We’ll now analyze the 3 cases of asset movements mentioned above:

1. Moving an Asset from CL into a Zone
2. Moving an Asset from a Zone to CL
3. Moving an Asset between Zones

Moving an Asset from CL into a Zone

In this case some entity Bob has an asset $b$ with commitment $com_\text{CL}(b)$ in CL and he wants to transact with it inside of Zone $z_A$.

In order for Bob to transact with $com_\text{CL}(b)$ in $z_A$, he must be able to prove to $z_A$ that:

1. $com_\text{CL}(b)$ exists
2. the corresponding nullifier $nf_\text{CL}(b)$ has not been spent