Scott Stornetta gave a presentation this Saturday, the 30th of May 2020, curated by the Government Blockchain Association Of UAE. The birth of the blockchain is among the many topics he discussed. Scott Stornetta and Stuart Haber’s three papers were references in Satoshi Nakamoto’s 2009 bitcoin whitepaper. Hence, there was speculation that Scott Stornetta is Satoshi Nakomoto. For what it is worth, he denied being Satoshi Nakamoto in the Japanese language, which he speaks.
In late 80s, Stornetta joined the legendary Bell labs, he had come from the West Coast; where he had been working at Xerox
The problem of immutability of digital records became a mission. Stornetta was trained as a theoretical physicist. He did not direct expertise in digital documents or cryptography, but he continued to pursue his interest.
Xerox and Bell labs encouraged work on open projects. You could work on anything as long you stated the problem. No manager directed your work, results did not have to be on a timeline. The advantage of an environment like that is that it throws together brilliant people from multiple disciplines, sparking open collaboration. Many storied and world changing products were born from these two cauldrons.
In Bell Labs, Stornetta met Haber, a cryptographer. Stornetta convinced Haber that the immutability of digital records was a problem worth working on. Their initial solution was based on hash functions and digital certificates. The document would be reduced to a hash. A hash is a well-understood and widely used concept in cryptography. A message digest or hash is a fixed length result (usually just a few bytes long), obtained from documents of different lengths. The hash changes even when one bit of the original document changes. The client who wished to timestamp the document sends a hash rather than the document to a Time Stamping Service (TSS). The TSS would then timestamp the document’s hash and certify it. A further extension is in the first paper they published, where a chain of documents to introduce a time sequence is in the section entitled “linking”. This would be a chain linking the documents together, each document’s certificate would contain a link to the previous document in the sequence.
The TSS is a single witness to the timestamp, it is open to subversion, either by corruption or by fraud. They despaired of finding a solution for the removal of trust on a single witness TSS. Haber suggested that they start writing a paper addressing their solution, without a solution to this problem. As they were writing the paper, they then lit upon a way to distribute the trust, by creating multiple certifiers of a timestamp. The users themselves would act as each others certifiers. This is in the section titled distributed trust. The creation of decentralized trust was on its way.
Hash functions and signatures do not address practical considerations by themselves. In the paper, Haber & Stornetta talked about two use cases. In one the actual timestamp of the document matters, in another the integrity and the tamper resistance of the original document matters. The first use case could be protection of digital lab notebook to preserve and authenticate primacy of discovery, in patents and the like. The second would be a way to hash digital documents that any enterprise is required to record, so that a later presentation would reveal tampering, it it did happen.
The trusted witness problem was practically solved by creating a witness to a weekly hash that cannot be subverted, turning the problem on its head, by enlisting the whole world to be a witness, in the form of a classified ad in the New York Times
The first solution to the problem of creating an immutable and irrefutable linked timestamp of a series of digital documents, which can be called a blockchain, is already there in Stornetta and Haber’s work, about twenty years before Bitcoin. This paper lay in wait for the genius of Satoshi Nakomoto to take it to new heights, years later. As Stornetta notes in his presentation, Bitcoin is not just a work of engineering, it is also a work of art; because of the creation of an emergent crypto-economic incentive using proof of work. The dream of a unimpeachable universal digital witness for the transfer of value started the whole blockchain revolution.
Stornetta says that the use case of digital document timestamping and the integrity of regulated corporate documents can be addressed in a more frictionless way, by a proper implementation on the blockchain. As befits the modern era, he is an advisor to a VC firm investing in blockchain based companies.
When asked what he would say to Satoshi Nakamoto if he had a chance, Stornetta said he would ask Satoshi to read the second paper. The second paper deals with safe upgrades, which is a governance idea that has been incompletely expressed in Bitcoin and creates much acrimony and division in the community. We will take this up in a later article on the topic.