Sismo Docs

Sismo Badges

Non-transferable/soulbound tokenized attestations
The Sismo protocol revolves around the issuance of non-transferable/soulbound tokens known as Badges.
Badges prove facts about a user’s digital identity—making them an ideal primitive for accessing the web3 social space. When integrated into applications, Badges act as the underlying infrastructure for access control and reputation curation.
Badges are derived from accounts (web2 or web3) imported into the Sismo Vault—an encrypted stash of secrets that facilitates a frictionless ‘Prove with Sismo’ web3 login experience.
Anyone can create their own Badge with no prior knowledge via the Sismo Factory.

Badge Characteristics

As Badges are tokens adhering to the ERC1155 standard, they can be integrated into any application (e.g. Guild or Snapshot) as an access control and reputation curation tool. Each Badge is a unique token within the same ERC1155 smart contract. Despite being part of the same collection, different Badges behave like distinct ERC20 tokens.
A Badge can be held by multiple users, with each user having a balance corresponding to their Badge’s level. Badge levels can translate to benefits such as increased governance voting power or a higher social reputation.
Badges correspond to attestations in an attestation registry governed by the Sismo protocol. As the Sismo protocol is fully modular, anyone can make their own Badges and even build or propose new attesters that award them. Each attester by the protocol’s governance platform has its own parameters for verifying user claims and issuing Badges—pathing the way for multiple use cases.

ZK Badges

ZK Badges are privacy-preserving Badges issued by zero-knowledge smart contracts such as the Hydra-S1 ZK attester. Users are awarded ZK Badges by the attester after providing the protocol with a zero-knowledge proof—a cryptographic proof that verifies a claim without revealing how it is true.
Zero-knowledge proofs allow users to privately leverage the social capital from their imported accounts—ensuring they can selectively reveal facts about their identities to access particular applications or services.

Use Cases

Badges can benefit users in a multitude of ways. Picture a user with two wallets—one public and one private. The user has valuable social capital on each wallet yet is uncomfortable linking the accounts. Using Badges, they can leverage their data in a frictionless and privacy-preserving manner.

Access gated applications

Badges ensure that the user only shares the information necessary to access a particular gated application instead of their entire web3 history.
For example:
  • Badges that allow prominent community members to vote on decentralized platforms such as Snapshot
  • Projects that use Badges to gate access to off-chain community platforms with Guild

Aggregate data from multiple sources

Thanks to the Sismo Vault, users can aggregate and granularly reveal data from multiple sources. This allows users to leverage data from all of their web3 accounts—giving them full control of their sovereign identities.
For example:
  • Combining data from multiple wallet addresses to mint an ‘Ethereum Power User ZK Badge’
  • Aggregating data from multiple accounts for a ‘Credit Score ZK Badge’

Import web2 reputation to web3

In addition to web3 identities, Badges can also be used to represent a user’s web2 identity.
For example:
  • An ‘Ethereum Twitter Influencer ZK Badge’ that does not reveal the exact Twitter account.
  • A ‘Proof of GitHub Contributions ZK Badge’ that does not reveal the exact contributor

Frictionless web3 logins

Sismo’s ultimate aim is to support a frictionless ‘Prove with Sismo’ web3 login experience. Projects will be able to integrate the feature into their applications—giving users a seamless UX when leveraging Badges.
For example:
  • A user imports multiple accounts into their Vault and uses their Badges to access gated applications by clicking a single ‘Prove with Sismo’ button
  • If the user does not have but is eligible for the required Badge, clicking ‘Prove with Sismo’ mints it on a fresh address