Comparing the Most Popular Decentralized Identifier (DID) Methods


mhrsntrk / September 25, 2023

Decentralized Identifiers (DIDs) are a key component in the realm of decentralized identity. They serve as the user's "self-sovereign' identity", pulling us away from the traditional centralized identity models.

To understand this revolutionary space better, consider the comparison between four of the most popular DID methods, did:ion, did:ethr, did:key, and did:web.


Developed by Microsoft, the did:ion method leverages the InterPlanetary File System (IPFS) and Sidetree protocol for executing transactions. This approach helps in creating scalable, stable, and decentralized public key infrastructure. A distinguishing factor of did:ion is its decoupling from the blockchain. It stores operations' batches on the IPFS, minimizing the required transactions on the chain and thus, leading to increased scalability. However, a potential downside might be the complexity of this method in comparison to others.


The did:ethr method operates within the Ethereum blockchain, enabling users to anchor their DIDs to their Ethereum addresses. This allows for robust interaction with smart contracts and other Ethereum-based operations. With less operational complexity than did:ion, did:ethr provides a straightforward integration within the Ethereum ecosystem. However, with Ethereum's gas fees issue, there's a possible pitfall concerning cost-effectiveness for high-volume users.


Unlike did:ion and did:ethr, did:key is oriented towards simpler, low-stakes uses. Its primary feature involves generating a new DID for each new public key pair, without any need for a transaction on a blockchain. These make did:key perfect for offline usage, testing or temporary identifiers. Notably, since it isn't anchored in a blockchain, it lacks the ability to associate multiple keys or enable key rotation and recovery.


The did:web method essentially creates DIDs anchored in common web domains. It links the trustworthiness of an existing domain to its associated DID, thus garnering user confidence quickly. Did:web's exciting aspect is its ease and compatibility with existing web infrastructure, including domains and SSL/TLS certificates. However, it diverts from the completely decentralized nature of the other DIDs by relying on traditional web domains, potentially going against some users' preferences for full decentralization.


While the listed DID methods vary considerably in their design, they remain united in their mission: enhancing user privacy and security by facilitating self-sovereign identity. Your choice depends entirely on your usage – from the simplicity and offline use of did:key, the Ethereum compatibility of did:ethr, the scalability of did:ion, or the familiarity of did:web. Each brings unique features to the growing decentralized identity landscape and demonstrates diverse routes to ensure user-centric control.