In a webinar earlier this year, Amazon provided information on Amazon Quantum Ledger Database (QLDB) and Amazon Managed Blockchain. From what was shown, it’s clear that the products are very early, still in preview, that they aren’t integrated, but that Amazon does seem to be moving forward based on a clear understanding of the different benefits of ledgers and blockchain.
Blockchain is just that, a chain of blocks of transaction data. The body of transactions creates a ledger, a record of all the transactions. In the blockchain world, each member of the blockchain network has a copy of the chain, which is why we discuss distributed ledgers. The core of the blockchain is the ledger, but to provide the openness for different blockchain implementations a lot of overhead must be added.
Two key aspects of the original blockchain concept are immutability and verifiability. The second means that each member of the chain can verify the chain. Each key has the mathematical term called a “hash” and those hashes are linked via formulas every member can use. The trust in the ledger is one aspect while blockchains can be both public or private depending on the application.
Amazon has realized this and the products they are rolling out are an attempt to address the scale of use cases.
Amazon Quantum Ledger Database
Amazon QLDB needs one quick caveat, or soap box rant. No, QLDB is not quantum, that database technology is still years away.
The trust in the blockchain model is important, even when a blockchain isn’t needed. To have the same kind of trust in a relational database, a lot of extra tables and code in applications to provide the audit trails that are native to blockchain.
Amazon created QLDB to address that problem for cases where a full blockchain isn’t needed. One example presented is a state’s licensing system, for cars, businesses and other entities that needs to be registered with the state. What the state wants to do is open the records for updates, for instance when a car is sold, but still control the data.
Imagine QLDB, in very simple terms, as a database that allows inserts but not updates or deletes. Since database entries can’t be changed or removed, there is immutability. Because all people who have access to the database can traverse the entire transaction history, you have verifiability.
An interesting addition to verifiability provided to people who use the system, given there is central control, is that each transaction uses a hash just as in a blockchain. Each user can access their own transaction chains and run verification on the hash table in order to ensure the that transaction has not been changed.
Amazon QLDB, in no surprise whatsoever, runs on AWS, so it is easily scalable and accessible to people in the cloud environment. It’s an intriguing entrant into the model database market, bringing ideas from blockchain’s distributed ledgers into the centralized world.
Amazon Managed Blockchain
As mentioned, the ledger is at the core of blockchain and can be extracted, but there are still interesting business uses for blockchain. What isn’t always needed is the public blockchain which is more easily attacked by bad actors. A limited and controlled group of blockchain members simplifies some security aspects and help performance through a far smaller group of servers that need to replicate transactions.
Amazon is looking at supporting a branded version of blockchain through initial support for Hyperledger Fabric and announced support for Ethereum to follow. The blockchain community is still new, so opensource matters. As the history of Unix, Linux, and other open source technologies showed, having a foundation or major corporation provide some certainty is a requirement to move beyond early adopters into a larger market. This seems to be a good choice for an initial blockchain option. Hyperledger Fabric is aimed at private networks while Ethereum has focused on public networks.