# Doctrina: Blockchain 5.0 for Artificial Intelligence
## 4 Doctrina  
The proposed blockchain architecture, Doctrina, is an innovative amalgamation of blockchain technology with artificial intelligence (AI). Doctrina is designed as a decentralized platform, aiming to provide a secure and efficient medium for executing AI models while ensuring the integrity and transparency typical of blockchain systems. This architecture distinguishes itself through a dual-network approach that blends the features of public and permissioned blockchain networks.  
Central to Doctrina's design is the adoption of Ethereum's smart contract framework, leveraging its established security and reliability features. These smart contracts are instrumental in managing interactions and transactions within the network, including the logistical aspects of AI model execution. The integration with Ethereum's proven system offers a robust foundation for the Doctrina architecture.  
The public network facet of Doctrina underpins the general transactional operations. It utilizes the Ethereum blockchain's immutable ledger for a transparent and tamper-proof record-keeping system. This transparency is key to the integrity of Doctrina, ensuring that all activities, data exchanges, and transactions are publicly verifiable and permanently recorded on the blockchain. On the other hand, the permissioned network in Doctrina is specifically engineered for the storage and execution of AI models. This network caters to the heightened need for privacy and controlled access, particularly pertinent to handling sensitive or proprietary AI algorithms and data. The permissioned network is restricted to authorized entities, providing a secure environment for AI model deployment and interaction. This design choice is pivotal in safeguarding the intellectual property rights of AI developers and in protecting the confidential data utilized by AI models.  
Doctrina's architectural integration of public and permissioned networks strategically balances security, transparency, and operational efficiency. The public network ensures the blockchain's core promises of security and transparency for general transactions, while the permissioned network provides a secure environment for AI model execution, isolating sensitive computations from the risks associated with public platforms. By logging only the high-level execution results on-chain, Doctrina guarantees privacy while maintaining transparency. The actual model execution occurs in the permissioned layer, safeguarding data and model integrity. This hybrid structure enhances both security and trust, offering a specialized, secure, and efficient infrastructure that supports the secure execution of AI models without compromising privacy or transparency.  
In contrast to other private blockchain solutions such as Hyperledger [9], which is not inherently designed for decentralized AI computation, Doctrina introduces a computation-centric protocol specifically tailored for on-chain AI execution. Private blockchains often rely on centralized or semi-centralized orchestration of computation, lacking the mechanisms to transparently validate and verify AI model performance across distributed nodes. Doctrina addresses this limitation by incorporating native consensus mechanisms for AI model verification, decentralized scheduling, and cryptographic proof of execution to ensure trustless model evaluation. Its design goes beyond simple transaction processing to facilitate the life cycle of AI models--including registration, execution, monetization, and governance--within a decentralized and interoperable framework. This makes Doctrina a purpose-built infrastructure for AI execution, rather than adapting general-purpose private ledgers for tasks they were not originally intended to handle.