Token Attestations: Proof of Ownership in ETH network

At AlphaWallet, we’ve begun the ‘Parcero’ project: an Attestation-based proof of identity that lets users associate an email or mobile number to identify ownership of an asset on the blockchain, without revealing their identifier or address.

digital identity ethereum

For the first implementation, we are developing an attestation-based Ticketing System, in partnership with DEVCON. Attestation can eventually be used with other use cases: Vouchers, Marketplaces, Online shop integrations, and much more.

What are the benefits? Overview:

  • For users: Privacy, flexibility and new utility for their tokenised assets.
  • For developers: Cost efficiency on implementation and new integrations.
  • For the ETH network: Onboard non-ETH users to the ETH standard.
  • For businesses: Limitless integrations across systems and control of a frictionless secondary market.

Help us continue building one of the best use cases for blockchain tokens in the real world.

Help us raising funds on Gitcoin

Why Attestation? Why Ticketing?

Most crypto users only use tokens as fungibles or NFTs on-chain. We are strong believers in a future where tokens are the most obvious choice to connect the rights and services in the digital and physical world.

Tickets are one of the best use cases to show how blockchain and crypto tokens can be used for real-world use cases. The proposed blockchain solution is not only as cheap and as fast as the current system, but also provides a host of features that traditional tickets cannot provide. These include:

  • Facilitating a frictionless secondary market, according to the smart contract’s rules
  • Elimination of ticket fraud
  • Limitless integration with a range of services

Attestation-based ticketing: benefits

Benefits for Developers & Users

For developers, attestation provides fluid integrations, secure interactions and new value-building opportunities. For users, it gives additional reach and utility for their tokenised assets, and security for their email or number identifier.

When using the attestation-based ticketing system, an Ethereum address is optional for those who don’t want to use blockchain at all.

Benefits for Businesses & Platforms

The attestation-based ticket can be made tradable within rules specified by the smart contract. This enables a frictionless secondary market to exist under the control of the original ticket-issuing business. 

Websites can recognise tickets attestations and authenticate the holder, providing extra incentives to the user like access to exclusive content, actions or discounts. This includes smart contract-based functions like voting. 

Benefits for the Ethereum Network

Attestation-based tickets are Ethereum tokens that can be used without a pre-defined ETH address. This gives a use case for non-ethereum users to convert and onboard the network, enabling massive ETH onboarding. It is one of the most tangible blockchain token use cases for the real world.

Users can create an Ethereum address before or after ticket purchases, or to use their own choice of address for online interactions.

As other event organisers and businesses adopt the system, it can bring millions of new users into Ethereum. Currently, there are 940 million unique digital ticket holders globally; if we can convert just 5% of them, we can bring in 47 million new users into Ethereum (half of the total Ethereum unique addresses as of this writing).

DEVCON implementation

Ticket Attestation will provide a cost-effective, flexible, and privacy-preserving path for Devcon and its attendees. It allows the attendee to create an Ethereum address before or after the ticket purchase, or to use their choice of address for online interactions. Via elliptic cryptography and zero-knowledge proofs, we have a protocol, safe protocol, to enable attestations for an email address without revealing it.

Read the full Devcon Implementation Proposal

Technical: Attestation

An Attestation based ticketing system ensures privacy, flexibility and cost efficiency for the blockchain implementation of ticketing. It involves two attestations:

  • Attestation #1: Links ticket with an email address (provided by the ticketing system at the time of purchase).
  • Attestation #2: [for crypto users] Links an Ethereum address with an email address (acquired by the user through a dApp browser).

Attestation #1 is the “traditional ticket”. It is issued by email after the payment is confirmed on the ticket purchasing website as a QR code and magic link. the user is not required to have an Ethereum address at this stage.

Attestation #2 can be issued by a service domain, such as The process of acquiring Attestation #2 would be a simple guided process. The user will visit a website, where he verifies their email to receive an attestation. This will be saved in the dApp browser as a cookie, or in the user’s wallet (if the wallet can recognise attestations).

When the user wishes to interact with a smart contract function, such as voting, the user will call the smart contract with Attestation #1 and #2. Together they prove that the transaction senders Ethereum address is that of the attendee. Such an implementation would preserve the privacy of the user, as these attestations do not reveal the actual email address. Please check out the safe protocol for more details.

Furthermore, a ticket’s proof of ownership can be generated from TokenScript, which allows a website to recognise Devcon ticket holders. This is useful for ticket holders to book services or to apply for a discount. We can create a sample website for service providers to copy.

Help us raising funds on Gitcoin

Process Flow

The attached swimlane diagram shows how the different parties involved in the ticketing process would use the solution to prove and verify the ticket’s authenticity.

Development Roadmap

We’re currently raising a fund grant round with Gitcoin. Help us develop one of the most promising use cases for the blockchain in the real world.


  • Smart Contract-Based Ticketing System (Shankai Sports’ FIFA2018 and EURO2020 implementation)

To be Done:

  • Integration of the ticket attestation system into the ticket purchase confirmation.
  • An email attestation service
  • Attestation JavaScript components for websites
  • Attestation library for smart contracts

After Ticketing:

  • Expansion of attestation-based feature to other markets

Help us raising funds on Gitcoin

Common questions

What is the used token standard?

Our preference is to use 721 compatible standards, as most of the infrastructures support 721.

How does this Attestation-based solution preserve privacy?

The Ethereum address is associated with the email through attestation. The ticket is linked with Email in attestation (off-chain, no privacy issue), Email is linked with Ethereum address (off-chain, no privacy issue), Ethereum address can be linked with Ticket (on-chain), can be further improved by applying zero-knowledge proof in attestation verification. Learn more with our Safe Protocol.

Does the user need to have an ETH address already?

Because the process to bind an ETH address with the ticket is independent of the ticket issuing process, users can get the needed email address attestation before or after purchasing Ethereum tickets.

Can the user trade his ticket?

The ticket can be made tradable within rules specified by the smart contract.

What happens if the user loses his ticket or ETH wallet address?

If the user loses his or her wallet, then the user can redo the process to get a new email address attestation of the original email.

Help us raising funds on Gitcoin

Have a project in mind?

We want to hear from you. Bootstrap your custom solution with our ready-to-market, white-label wallet. Or co-create with our expert team to tokenise your business model, at a fraction of the time and cost.