The zones or Blockchains share the information with each other

through a hub with the help of the IBC protocol, as shown in Figure

11.4. The hub keeps a check on the “double spending” by the zones.

It also keeps track of all the zones and their headers and provides

the proof to the other zones during the transactions. Refer to Figure

11.4, as follows:

Figure 11.4: Hub generates trust in Cosmos

Hence, the zones do not need to trust each other. They just have to

trust the hub.

These types of interoperability works for the Blockchain zones that

can abide by the Tendermint consensus. However, when it comes to

interactions

between

a

Tendermint

and

a

non-Tendermint

Blockchain, such as PoW based Bitcoin or Ethereum-I, then we have

to introduce a “Peg Zone” or a Blockchain that tracks the state of

another Blockchain, as represented in Figure 11.5 as follows: