Amazon Web Services recently announced the preview of Quantum Ledger Database (QLDB), promising a centrally administered immutable data ledger within AWS. We predict that QLDB and other competitive centralized ledger technology offerings that will eventually emerge will gain at least twenty percent of permissioned blockchain market share over the next three years.
My colleague Nick Heudecker and I just published a research note on the AWS announcement See Amazon QLDB Challenges Permissioned Blockchain analyzing the challenges and benefits of permissioned blockchain vs. QLDB (which by the way has no quantum computing technology built inside it). (We will soon publish a follow-up research note that analyzes decentralized ledger technology vs. centralized ledger technology vs. blockchain used for a ‘single version of truth’).
As noted in our research, Gartner is witnessing four common denominators in promising multi-company or consortia-led blockchain projects, of which AWS QLDB satisfies the second and third:
- The majority of industry (or consortia) participants need a distributed ledger where every participant has access to the same (single) source of truth.
- Once written to the ledger, the data is immutable and cannot be deleted or updated.
- A cryptographically and independently verifiable audit trail is needed to satisfy the use case, for example to prove the provenance or state of an asset.
- The various participants in the blockchain consortia all have a vested interest in its success; and there is no single entity in direct control of all activities.
These features are not readily available using traditional legacy technologies and are core components to user interest in adopting blockchain and distributed ledger technology. QLDB is optimal for use cases when there is a trusted authority recognized by all participants and centralization is not an issue. Blockchains are optimal when there is no trusted authority and centralization is indeed an issue.
Figure 1: Overview of Amazon QLDB
QLDB supports a simpler and more cost effective way to implement what many permissioned blockchain use cases try to achieve: a cryptographically and independently verifiable audit trail of immutable data. This is useful for establishing a system of record and for satisfying various compliance requirements.
While QLDB has yet to be proven outside of AWS’ internal use cases, the centralized ledger promises to be simpler for organizations to implement than permissioned blockchains governed by consortia. Further, in their current state, most permissioned blockchains don’t yet use key tenets of blockchain technology, i.e. decentralized consensus and tokenization. As currently implemented, permissioned blockchains justifiably call into doubt their value add over centralized DBMSs.
Over the next five years, Gartner forecasts that permissioned blockchains will merge with public blockchains at the infrastructure level, with distinctions ensuing at the transaction level so that transactions are either public or permissioned. This will enable permissioned (aka private) transactions to benefit from complete decentralized blockchain technology including decentralized consensus and tokenization. (See “Predicts 2019: Blockchain Technologies”).
In the meantime, some narrow benefits from permissioned blockchains are intrinsic to QLDB – i.e. immutable data and cryptographically verifiable audit trails. QLDB does not benefit from decentralization and independent copies of the ledger that come with permissioned blockchain technology – features that further promote data security and integrity.
Nonetheless, QLDB will satisfy the second and third of the four common denominators noted above and many users will no doubt find this type of centralized ledger appealing.