Historeum addresses a significant limitation within the Ethereum Virtual Machine (EVM): the difficulty of efficiently accessing and querying historical on-chain data. In the current EVM infrastructure, developers and users face challenges when trying to retrieve past data, as traditional methods often rely on centralized oracle services.

Previous solutions, such as The Graph, Covalent, and Dune, have provided decentralized APIs to tackle centralization issues. However, these solutions still required contracts to depend on centralized services for data retrieval.

Historeum was developed to overcome these challenges by enabling direct access to historical data through smart contracts within the EVM environment.

Core Features

Historeum is a Layer-2 solution that introduces "Archive Storage" to its architecture, allowing direct access to historical data on-chain. This storage system is fully integrated with our modified EVM, resolving the data accessibility limitations previously encountered.

The OP Stack has been modified to support these features, allowing smart contracts to access historical data through new commands introduced in the EVM.

Historeum also introduces a new read-only keyword, "caerus" in the Solidity language, enabling developers to interact directly with historical data within their smart contracts.

Practical Use Cases

Historeum offers a wide range of applications, demonstrating its ability to address various blockchain challenges:

• Time-Weighted Average Price (TWAP): Historeum allows for efficient calculation and updating of TWAP with a single query, spanning both past and present data.
• Airdrops: Historical data can be verified to facilitate accurate token distributions.
• Reputation Systems & APR Calculations: Historeum's versatility extends to reputation systems and financial services, where access to historical data is crucial.

In developing Historeum, our team thoroughly explored the intricacies of blockchain technology, focusing on enhancing the Ethereum Virtual Machine (EVM).

• Modifying the EVM: The core of Historeum's innovation lies in modifying the EVM. By adding new opcodes and functionalities, we enabled smart contracts to query historical data directly.
• Solidity Enhancements: Introducing the "caerus" keyword in Solidity was a significant achievement. This required a deep understanding of the Solidity language and its compiler, Solc. We modified the compiler to recognize and compile the new keyword, allowing seamless interaction with historical data.