ZkCloud and Zero knowledge are two different concepts.
ZkCloud refers to zero knowledge cloud computing, which is a cloud computing model that protects user data privacy. It uses the Zero-knowledge proof technology to ensure that cloud service providers cannot obtain user data content when processing user data. Users can store data in the cloud, while cloud service providers can only calculate the data and cannot view the specific content of the data. This approach can effectively protect users’ privacy.
Zero knowledge is a Cryptography concept, which means that in the interaction process, the verifier can prove a statement to the verifier is correct, but does not disclose any information about the statement. In Cryptography, zero knowledge proof can be used for the verifier to confirm the authenticity of a statement without knowing the specific content of the statement.
Simply put, zkCloud is a cloud computing model that applies Zero knowledge technology, where Zero knowledge is the technology and zkCloud is the application. If Zero knowledge is compared to a universal chassis of a car, then zkCloud is a branded car built on a universal chassis.
After understanding the differences between the two, let’s talk specifically about what zkCloud is?
ZkCloud is an off chain, untrusted computing environment where programs can be executed privately, securely, and cheaply, with no restrictions on runtime. With these features, zkCloud has solved the most challenging problem faced by blockchain to date: the privacy dilemma.
How to solve the “privacy dilemma”?
For blockchain protocols, there has always been a trade-off between privacy and programmability. So far, most projects in the market have developed in the following two directions
Most blockchains prioritize programmability at the expense of privacy, or protect privacy at the expense of programmability, scalability, and performance. So far, no project has been able to achieve both fish and bear’s paws. That’s why the upper right position in the above image is empty. Aleo can effectively fill the need for programmable privacy through what we call zkCloud.
How does zkCloud work?
In a typical public blockchain, program execution occurs on a global ‘virtual machine’ (VM), run by each network node. This means that every node in the network must be recalculated and given every step of the program. This not only leads to low efficiency, but also reduces running speed and increases the cost for end users. Moreover, due to the fact that this virtual machine must be able to access relevant information, privacy protection is limited.
Through zkCloud, Aleo overcomes these limitations by separating the application runtime from the state maintained by the blockchain. Combined with the Zero-knowledge proof capability, this enables Aleo to achieve full programmability and privacy, as well as high transaction throughput relative to the virtual machine model on the chain.
ZkCloud is an offline, untrusted execution environment where independent entities or transactions that do not wish to disclose their identities interact with each other.
These transactions, whether simple point-to-point transfers or complex financial applications, hide interaction details (such as participants, amounts, smart contracts, etc.) in the transaction process through Zero-knowledge proof. External proof is only the final result of this process and the only ‘evidence’ of transactions (or a series of transactions, such as transactions in complex applications) that occur in zkCloud.
Protected transactions connect zkCloud with the Aleo blockchain, consuming and creating records on the chain to modify/update the status of the application. The node (and other users) verifier can confirm the authenticity of the transaction without knowing the specific details through Zero-knowledge proof, thus completing the verification.
We can visualize the interaction between zkCloud and Aleo blockchain as a “shadow”.
When you see a shadow, you know something has created it, but it is difficult to identify the details or accurately identify what it is. Although programs run on zkCloud with varying complexities, nodes on the Aleo network can only see the “shadows” generated by transactions executed within zkCloud. Because Zero-knowledge proof does not disclose any information to them, when these nodes (or other third parties) see the transactions submitted to the chain, they can know that something is happening. Unless one party in the transaction intentionally discloses some data, they cannot determine any specific information about the interaction.
Due to the separation of computation and state, zkCloud provides unlimited application runtime. Programs running in zkCloud can take one second, one minute, or one day; Simply submit the hidden transaction at the end of the calculation. Compared with Ethereum and other on chain execution models, this provides the possibility for more kinds of applications, because the running time of the program is not limited by “Gas”.
In addition, the off chain execution in zkCloud means that the privacy of users when interacting with applications has been greatly improved.
As only proof is submitted to the chain, no one can see or utilize any knowledge of transaction details. In addition, transaction throughput will be significantly improved as Aleo nodes only verify the proof, rather than running the program.
Even though Aleo has these additional advantages over other encryption methods, Aleo will not make any compromise on security, because Zero-knowledge proof will ensure correct program execution in Cryptography during the transaction process. This is in stark contrast to other blockchain and many second tier solutions, which only provide state transitions in cryptoeconomics. But in Aleo, the validation program only needs to prove that it was executed correctly or not executed. Eliminated the need for users or smart contract developers to collect and verify more personal information.
As our digital life becomes more and more important, we need to hold more interactive information in our own hands. In this case, zero knowledge Cryptography represents the next digital revolution. It is the basic principle of protecting private information in public transactions through zkCloud. Aleo provided the building blocks required to build these applications and overturned our current thinking on blockchain scalability and privacy.
