Create tamper-evident databases with Ledger

- [Instructor] Azure SQL Database and SQL Server 2022 introduced a new feature that allows you to attest that your database hasn't been tampered with. This feature called Ledger is easy to implement and it takes a unique approach to database security. Ledger is built on top of a cryptographic blockchain. As transactions are executed on the database, a record of each modification is saved along with a cryptographic hash of the previous transaction. This forms a linked chain of modifications that record the entire history of protected tables. The ledger blockchain is used to protect two types of tables in a SQL database. Updatable ledger tables can include records subject to insert, update, or delete queries. As modifications are made to rows, a parallel system version, or history table is used to record all modifications. The other type of table is called an append-only ledger table. This type will only accept row inserts. Once a row is added, it cannot be updated or deleted from the…