The Future is Now: Digital Signatures move on to Blockchain Technology

An authority issues certificates (say, an education institute). These certificates are stored on a centralized document management server or a distributed file system like IPFS and signed with a cryptographic function.

The document URI, metadata, and the content hash are then encrypted and stored on the blockchain digital ledger and attached to the user’s digital identity. The system issues a unique authenticity token, which identifies the document in a non-questionable way.

The original document data is never stored in the blockchain, only the document’s hash.

Using a distributed ledger makes the solution decentralized and provides the highest possible security, efficiency, and compliance.

If a document’s authenticity is ever questioned, the “off-chain” file can be re-hashed later and the resulting hash compared to the “on-chain” value.

If the hash values match, the document is authentic, but if anything is modified, even just a single character, the hashes will not match, making it obvious that a change has occurred.

Let’s say that, at a given point, a user needs to present their certificates to a third party, like an employer. He can share the authenticity token with the third party for verification. The token works as the file’s contract address, as it contains all the necessary information to verify that the document exists and is authentic (not counterfeited).

Processing documents and any unstructured data and their metadata and integrating them with blockchain creates immutable and independently verifiable records of transactions. There is now a way a proof of existence and authenticity for these digital assets.

Proof of existence refers to creating an unalterable date and time stamp for a specific object. It means that you can prove that a certain information object, like an email, document, or image, existed at a certain point in time.

Proof of authenticity asserts that an object is authentic, i.e., that it has not changed since it was stored at the indicated time instant. This is accomplished by digitally signing an object and thus creating a hash, its unique identifier. The identifier gets then committed into the distributed blockchain ledger, and the transaction gets timestamped as well.

Since every entry in the blockchain is immutable, this means that you have proof that this specific object existed at a certain point in time.

Why should we use blockchain to sign and verify digital assets when solutions for electronic signature already exist and are broadly adopted in the industry? Here is why:

• Digital signatures stored on a blockchain live independently of the object the signature refers to. There is no need for a central certificate authority or central timestamping server, which are the typical dependencies of existing e-signature systems.
• You can achieve parallel signing and independent verification, with or without the object itself.
• You no longer store digital signatures inside the document, as with traditional e-signing solutions. With the old-school solutions, whoever needed to check if a document is signed would have full read access to all the content in the document.
• By signing documents on a blockchain, the object is not changed by the signature, enabling you to sign documents in parallel and implement business rules based on mandates, 4-eyes, majority vote, seniority, and others.
• Lastly, but not less important, you can register multiple actions in a sequence on a blockchain. Each registration is linked to a specific case, document, and task performed by the parties involved, creating a chain of transactions: an auditable trail. This audit trail can then be verified by authorized third parties, providing transparency, compliance, and, most importantly, trust.

CB Blockchain Seal for SharePoint  is the ready-to-use solution for Microsoft SharePoint that allows you to digitally seal the documents you store in SharePoint using blockchain technology.

Adding digital signatures to PDF files or Word documents is probably the most obvious use case, but this solution works with virtually any kind of document or file.

You can prove that no-one tampered with the document the digital signature was added to from a certain moment onwards. The fact that the digital seal is timestamped is essential, for example, to protect intellectual property.

To learn more about this innovative technology, watch a quick demo here: https://youtu.be/HGCbHcN_CK8

• Blockchain is a technology that can assist with the verification of tamper-proof documents.
• Signature and verification are separate processes that do not depend on a central authority.
• CB Blockchain Seal for SharePoint allows us to sign documents and store their seal on a blockchain digital ledger.