Polkadot are trying to create awareness about the fact that it is due to the availability and validity protocol that Polkadot is able to efficiently shard while maintaining strong security guarantees.

The Availability and Validity protocol (AnV) is that which makes possible for the network to be efficiently sharded.

The Polkafot.Wiki states there are six phases of the AnV protocol:  “Parachain phase.  Relay chain submission phase. Availability and unavailability subprotocols.  Secondary GRANDPA approval validity checks.  Objection procedure for fishermen.  Invocation of a Byzantine fault tolerant finality gadget to cement the chain.”

Anyone who wants to understand the nuances of the security guarantees facilitated by the shard should check the entire publication.

Polkadot was created and they are continuing to develop with a focus on their belief that no single blockchain can do everything and they strongly believe that the future is multi-chain.

Polkadot have a detailed plan of how they can accomplish this mission with bridges to other networks, and what bridges are currently being built.

It is well known that Web 3.0 is the next generation of internet, and this version is considered to be a fully functional and user-friendly web, each of our identity and data is our own and this is to be safely secured from any central authority.  This is made possible by the decentralized blockchain technology. In a way of keeping up with this vision, Polkadot have been created with the belief that there is no single blockchain which will be able to everything and thus in a way reinstating that the future is multi-chain.

The numbers and the size of the blockchain networks is growing day by day.  And, each of these blockchains are mainly cut off from one-another and they function like islands which have their own communities and economies and they behave like they will not be able to exchange information or value with the rest of the world. This is against the principle of decentralization and is representative of the Balkanization of the already existing centralized Web 2.0 world.

The very concept of a blockchain bridge is the ability to connect and permit the transfer of tokens and/or arbitrary data from one blockchain network to another. Thus, both the chains will be able to have different protocols, rules, communities and governance models; however, a bridge facilitates a compatible way to interoperate securely on both sides of the interacting blockchains.

Polkadot in this process are placing their confidence in trustless bridges, where users need not place their trust in a single entity or authority; however, the trust is on the mathematical entity built in to the code.