Key differences between Hyperledger Aries and Hyperledger Indy?

Question

Both Hyperledger Aries and Hyperledger Indy are platforms for building distributed ledger applications for identities.

What are the main differences between them? When to choose one over the other to implement a blockchain solution?

Answer 1

Aries is the agent (client) part of a decentralized identity (ledger, DIDs, verifiable credentials) application that is intended to be agnostic to the underlying ledger/DIDs/verifiable credentials layer.

Indy is a decentralized identity implementation including support for a ledger, DIDs and verifiable credentials.

Initial Aries work was to move the agent work in Indy to Aries, and so the first working versions of Aries use Indy underneath for the decentralized identity components. Over time, those components will become pluggable, and additional decentralized identity components will be supported. Thus, major parts of the indy-sdk will be deprecated, as they are implemented in Aries.

For building solutions, you should always be looking at Aries to start. You will need to know what Indy does, but not the details. The only time you would need to dive into Indy is if you what to extend its capabilities to support your use case.

Answer 2

The question is clear, what choice to make between Aries and Indy, we could also rephrase as follows: where to start from? Indy represents, certainly, a base layer, Aries, at the moment, is the better choice for building identity app. Indy, infact, provides: Blockchain network, DID’s implementation, and all features related to verifiable credentials. Aries, on top of it, helps to build apps which can communicate over peer to peer network through secured communication channel: DIDComm. From the user interaction point of view, Aries is integrated with identity apps and internally talks to Indy. Aim of Aries, obviousely, is to build an interoperable communication layer that can be connected not only to Indy but also others blockchains framework. Indy, as the first project in the Hyperledger family to build a decentralized identity, offers a real-time view of the transactions and its architecture is based on self-sovereign identity which enables users to have complete control over their identity. At the very beginning Indy was good to build an identity solution but, clearly, it lacks a peer to peer communication which is the heart of identity solution. Aries has filled this part. For building solutions there are lots of things that need to be considered but you should look at Aries to start