SCF #6

Blocknify allows you to easily add legally binding e-signature to any Stellar transaction with privacy and trust built-in.

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Our solution enables users to legally sign documents using the Stellar Network as a notary. Many payments are made according to a contract, such as loan agreements, payments around a service or product, tokenization agreement, equity agreement, and many others. However, payments are often detached from their context. Our solution allows you to tie a legally binding e-signature and PDF to your payment. This process ensures that if there is a dispute, the proof can easily be provided, and all the needed information can then be validated within the Stellar transaction.

We believe in the power of lowering the barrier to operate in a fair system. Legal contracts are vital to setting the context and terms of a business transaction so that all parties can be treated fairly.

Currently, our product allows you to:

  1. Sign or send a document (PDF) to be signed within two clicks using our chrome extension or initiated via our API.
  2. Signers receive an email with a unique link to sign the document via our web application (no installation needed).
  3. Signers verify themselves via SMS (ID verification pending), create a signing PIN, and then view their document and sign.
  4. The signature is packaged with the information we have collected from the signer, hashed, signed (with the signers private key), hashed again, and submitted to the Stellar Network as a Memo.
  5. Once all signers have signed the document, everyone receives the final document with an attached audit trail. This audit trail contains all the needed information to verify any signature at any time without requiring any input from Blocknify and the linked transaction on
  6. The audit trail contains the document fingerprint (hashing of the document's visual content) and the signer's public key, name, phone number, and raw signed data. At any time, a signer can use the audit trail and instruction to reconstruct any one of the attached signatures and going from their identity, document, time information to our signature hashed posted to the Stellar Network with standard tools.

With additional development funds from SDF, we will be able to:

  1. Signers will have two options to tie an existing Stellar account via SEP: 0007 or Albedo.
  2. The poster will be able to request payment within a specified asset and sign the document.
  3. The signer will then be able to select which asset they will pay with.
  4. We then create the transaction with the signature and asset transfer. This transaction will then be presented as a URI link, QR code, or requested for signature from Albedo. The transaction will then be signed and posted to the Stellar Network.
  5. We then monitor the transactions for the account and confirm the integrity of the transaction.
  6. Once all signers have signed the document, everyone receives the final document with an attached audit trail. This audit trail contains all the needed information to verify any signature at any time without requiring any input from Blocknify and the linked transaction on

To verify signatures at any time, signers can use our open-source tools and the final document with the attached audit trail. This tool will then recreate the document fingerprint hash, pull the signer's information, recreate the signature hash, and then match the hash and account within the Stellar network's transaction.

What this means for the Stellar ecosystem

It lowers the barrier to creating fairer and legally enforceable asset transfers within the Stellar ecosystem. An additional tool for transacting assets on the Stellar network. Our APIs can easily be added to any existing platform or solutions using the Stellar network by using an iframe. We provide white labeling of our web application and chrome extension. We support templating to allow for easy PDF generation. Ability to get documents signed in complete privacy.

We know creating a legal document itself can be unfair. Therefore we would love to work with our legal network and other for-profit and non-profit groups to make it easier to generate contracts. Our template solution allows us to sign the template, allowing signers to feel safe that this "standard" contract is a word for word copy of the known standard agreement.

How are we different from other e-signature solutions:

We have focused on creating a solution where technology creates trust rather than marketing.

While there are many other e-signature solutions, however, almost all of them are centralized black boxes requiring you to trust them / rely on them. Keep in mind most of these solutions are quite old (in technology years) and have the benefit of the doubt from their users that "they have this figured out." For example, many cloud e-signature solutions keep a copy of your document as the source of truth, control the identity, and key management. This is the easiest way to do this process. One issue is that you must rely on them to verify the document signed and provide all the identity records and internal system time stamps, as they only provide some basic information. These programs are also expensive. Other non-SaaS methods are privacy-focused but are painful.

While I don't believe they have any malicious intent, we see this centralized black box as an unnecessary risk, especially with new technology (e.g., Stellar).

Instead of holding the document forever, we came up with a way to clean the document and verify its visible elements on the client-side. Files can collect a lot of noise as time goes on; however, a signature is only concerned about the visual elements. We use standard PDF parsing to breakdown the PDF to its visible elements and create hashes of hashes. This process ensures that even if one pixel is changed, then the document fingerprint is entirely different while ensuring the document's complete privacy. However, this also enables us not to require centralized control or require Blocknify to store a clean source of truth version and allows our signers to reverify their documents at any time client-side.

As other solutions create their black box immutable timestamps, we use Stellar as our immutable public witness.

Instead of holding all the information in a black box and making you trust us, our signature can be independently verified with the attached audit trail sent out to all the signers after everyone has signed.

We support our goal of building trust and privacy in three ways.

First, our solution is built to the specification of one of the most strict e-signature laws, eIDAS (EU) advanced electronic signature. By following eIDAS, we also satisfied e-signature laws of over 60+ countries who follow eIDAS, such as Switzerland, or have less strict rules. Due to our signatures being transparent, signers can verify how we created their signature, ensuring we follow the rules. Our e-signature solution is currently being used by law firms (, financial services, and other regulated industries.

Second, our signatures and document verification are constructed entirely client-side and allow for decentralized verification. Because you can't blindly trust the front-end, the signature should be validated. For our public solution, we validate signatures on our backend. However, we can delegate this verification to another backend. Our new library will provide an easy way to verify the document and signature info against the posted stellar transaction. This will allows us to still facilitate signatures without needing to view any sensitive information. In the future, we would like to use zero-knowledge-proofs for all identity info, which allows us to verify the identity information on our backend without knowing the real information (let us know if you have experience in this!).

Third, our audit trail contains everything you need to independently verify any signature, without any data from Blocknify. After every signer has signed the document, a final document is sent with an attached audit trail. This audit trail is just the collection of the signature documentation, and because of that, it can be constructed without Blocknify for high privacy uses. It has all the needed information to re-construct signatures and independently verify each signature on the Stellar Network. While this can be manually done today, we're currently working on making an open-source version of our signature verification to make it even easier to validate.

Blocknify has been around since early 2018

We graduated from the F10 accelerator (managed by the Swiss Stock Exchange) and StartupYard (the oldest accelerator in CEE). We have clients and partners from financial service companies (Raiffeisen International Bank), law firms (, and other regulated industries (

Why the Stellar Network?

In beginning, we used a private Ethereum network. We then tethered our private network to the main net for accountability and control of our cost. However, running our own private network created additional complexity and undermined our mission for trust to be built-in.

We choose Stellar because of the ease of use, excellent documentation and community tools, mission, cross-currency transactions, specialization around asset-backed tokens, and low cost.

We believe in Stellar's future and the ability to lower the barrier and cost of transferring assets anywhere in the world. We believe Stellar's mechanism of creating trust and legitimacy is a massive factor in reducing the barrier of using DLT. We hope we can play our part in lowering that barrier by making it easier to sign contracts and tying them to asset transfers to help encourage fair and safe transactions.

What will we do with the funds?

We are only in step one of our Stellar Integration. Currently, we use our account to post the signer's signature hash to the Stellar Network (the signer uses their key to sign the document). Our Chrome extension currently supports all chromium browsers (Chrome, Brave, Edge, etc.), and signers can sign on any device through our web application.

We plan to finish step two, three, and four in our Stellar integration with these additional funds.

  • Step two: Allow our users to create their Stellar account.
  • Step three: Allow users to use their existing Stellar account to sign documents and submit their signature to the Stellar network.
  • Step four: Allow users to tie their document signature to a payment.
  • Step five: Allow users to request a payment, which will be paid with the attached signature.
  • Step six: Allow users to pay in any Stellar token.
  • Step seven: Enable complex signature and payment use cases.

Links (our free plan allows for 20 documents per month) - If you are curious to see how you verify a signature from signature information to the posted hash on the Stellar Network, you can find a step-by-step process on our help site. - You can find an example of a signed document here.

You can see the transaction on Stellar by clicking on the paging token after "Signature:" and if you want to see the signature information, you can copy the data URL that is linked in the header of "Signature:" (this allows us to hide detailed information while not confusing non-tech users).

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