Using blockchains as an alternative to PKIs for digital signatures

The traditional technical environment for a digital signature is the public key infrastructure (PKI). Digital signatures are also used to implement electronic money such as Bitcoin. However, Bitcoin uses a new technology, the blockchain. This new technical infrastructure can also be employed to sign documents. But what are the benefits?

A public key infrastructure allows for creating digital signatures by the owner of a private key and verifying the signature by anyone with a corresponding public key. A blockchain is a gobal database that allows for safely authorize and verify transactions (transfer of funds). A blockchain can now be used to build a digital signature infrastructure with some unique properties.

Multiple Signatures

With a blockchain it is possible to support quorums such as 3 of  5 signers (or any other combination) must sign a document in order to make the signature valid. This feature can also be used for counter signatures.

Time Constraints

In order to make a signature valid we can set a time constraint for a document to be signed.

Time Stamping

Every transaction which is recorded in the blockchain is time stamped within minutes.

There are some other features that differentiate a blockchain based digital signature scheme from a traditional PKI based scheme. And, although this technology is still in its pioneer phase it has already been adapted in some applications of the financial industry.

We are planning to adapt our 3-Heights(TM) Security Tool to support the interfaces of selected blockchain service providers.

I would be very interested in your opinion about blockchain based digital signatures. If you know of current and future applications, requirements and benefits please share it and post a comment.