Azure Confidential Ledger or ‘ACL’ is a lightweight and flexible managed decentralized data platform, built on top of Azure Confidential Computing and Intel SGX. Backed by blockchain technology, multiple parties can add data entries in a secure and tamperproof way to ensure data integrity whilst allowing flexibility in the data and approach.
Azure’s confidential computing technology and hardware can secure data during processing, to ensure confidentiality of data end-to-end rather than just when at rest or in transit. This allows for processing of sensitive and regulated data in the cloud, to enable specific use cases such as cross-organizational data sharing, data combination, and processing of large datasets to train AI models without exposing the data to others.
Azure Confidential Ledger runs on similar principles to those used in Azure SQL ledger tables, which we explored previously for Microsoft Build 2021. Azure Confidential Ledger gives us the same level of trust and integrity, without the need for a managed SQL database or dedicated SQL server. Entries can be quickly added to the ledger as and when they occur, with receipts for each transaction to validate each entry. Entries can also be read from the ledger, so a full history can be established, without the ability of any party to tamper with the historical content.
Entries can vary, from the short and simple, to verbose or unstructured data formats. This provides great flexibility in what can be logged to the ledger, making Azure Confidential Ledger suitable for many use cases. Data formats can be changed or adapted over time, and entries don’t have to conform to a single standard from the point of creation, so confidential ledger can evolve with the problem space it has been implemented in, while retaining the history of data.
Using Azure Confidential Ledger is one way to support secure multi-party machine learning. For more information about attestability for the masses, or to add comments, the blog post is available in full at Azure Confidential Ledger – attestability for the masses (avanade.com) - for Azure Confidential Ledger itself, Microsoft's documentation is the place to start reading up.