Introduction to ICP
ICP is a general-purpose blockchain that hosts canister smart contracts. It is designed to provide a World Computer that can replace traditional IT and host a new generation of Web3 services and applications that run solely from the blockchain, without the need for traditional IT. It can also play the role of Web3 orchestrator, by interacting with traditional blockchains.
It has a completely unique design that reflects a ground-up rethink of blockchain architecture and the application of modern cryptography, which can be traced back to 2015. It was built by the largest ongoing R&D effort in crypto, which has employed many notable cryptographers, computer science researchers and engineers. The blockchain underwent genesis in May 2021 and became part of the public internet.
The Internet Computer blockchain's protocols leverage novel chain key cryptography to combine multiple subnet blockchains into a single blockchain. This allows it to horizontally scale the total volume of hosted canister smart contract, and their computations and data, without limit. These smart contracts run at web speed, and with web-levels of efficiency, and uniquely, thanks to the blockchain architecture enabled by chain key crypto, can process HTTP requests and directly and securely serve interactive web experiences to the end-users of web3 services, without need for trusted intermediaries (whereas on other blockchains, the web experience users interact with is generally built on centralized, insecure and trusted servers or cloud computing services).
Through these kinds of unique capabilities, the Internet Computer provides a platform that can be used to build mass market web3 services that run 100% on-chain, without any need for traditional IT, such as web servers and databases running on cloud computing services. The longer-term objective is that the Internet Computer will completely replace traditional IT, creating a blockchain singularity, in which everything runs fully on-chain in powerful new forms where it is unstoppable and cannot be hacked.
The development of the Internet Computer has heralded numerous notable technological developments, such as chain key cryptography and programming languages such as Motoko. In another notable advance, the Internet Computer hosts an advanced DAO within its protocols, called the Network Nervous System, which provides the community with direct control over network governance, and can upgrade the protocol running on its network nodes, without requiring the network to fork. The network's utility token is ICP (see Roles of the ICP utility token).
A recent new technological advance has extended the Internet Computer's chain key cryptography protocols. This has enabled smart contracts hosted on the Internet Computer to directly interact with other blockchains, without need for dangerous centrally-controlled bridges or wrapping (see trustless multi-chain web3 using the IC, and extending Bitcoin, Ethereum and other blockchains).
For example, a canister smart contract hosted on the Internet Computer can create bitcoin addresses, and directly send and receive bitcoins on the Bitcoin ledger as though it were hosted by the Bitcoin network itself. This is possible because chain key crypto enables blockchains to create public "chain keys", for which their nodes can create corresponding signatures. Recent work has now made it possible to create ECDSA chain keys. Since ECDSA is the signature scheme used by most other blockchains, this means the Internet Computer can create TX on other blockchains.
Future work will enable its smart contracts to directly interact with other important blockchains such as Ethereum. This also leverages other important features such as HTTPS outcalls. As a consequence, many believe that the Internet Computer will play the role of an orchestration layer that combines different blockchains in the web3 environment, and helps combine them with off-chain services and systems, such as Web 2.0 services and enterprise systems, in a trustless way.