[H]e engraved on a stone the whole story.The Epic of Gilgamesh 61 (N. K. Sanders trans., Penguin Books 1960).
Bronze age rulers erected steles so that their words would endure. We do that today with blockchain.
Almost everything we know about ancient Egypt, for example, even the name “Ramses,” comes to us from steles and other inscribed stones dug out of the sand as many as 5000 years after pharaohs ordered them carved. Inscriptions in stone endure because stone is difficult to work. Hard to destroy; harder to recarve in ways that do not betray the fact that recarving has taken place. When the pharaohs made a record in monumental stone, they made public records the authenticity of which could be verified, even by scholars working millennia hence.
But that’s just what blockchain does for the internet. Blockchain inscribes information onto computer memory in a manner that, like a stone carving, is very difficult to change.
Making the information stored in computer memory permanent is not easy, because computer memory is engineered for rapid change. Computers record data by rearranging the electrons adhering to the physical material of a disk, tape, or chip. Changing the data therefore requires no more than an application of electricity.
The ease with which data can be changed in computer memory is the source of computing’s power, driving the cost of communication almost to zero. In the millennia following the carving of the first steles, which are very costly to create, civilization succeeded at finding increasingly inexpensive methods of recording information. But even the most inexpensive methods devised, such as paper, still required costly manipulation of matter on a macro scale–the application of inks–to be useful. Computer memory outdid all alternatives by requiring only manipulation of the utterly insubstantial electron.
But with the reduction in costs came impermanence. You, or a hacker, could change your data without leaving a trace of what came before. Indeed, without anybody being able to say for sure whether your data had been changed at all.
Blockchain tries to solve the problem of data impermanence, while preserving all of the advantages of electronic computing and communication, by storing data in an encrypted format. Changes to the data not made using the proper format can immediately be detected by readers. So merely changing the data electronically, while just as easy as it has always been, won’t fool readers, who can see that the changes don’t conform to the standard.
Indeed, the fact that blockchain solves the impermanence problem without changing the basic ease of storing data with electrons means that blockchain allows computers to continue to communicate quickly and cheaply. Data endures because it has been tied to encryption cyphers, not because it has been tied to the physical world, as in the case of a pharaoh’s steles.
A different approach to the problem of internet permanence would be to rig up a computer system in which robots would store data by automatically carving the data onto stone tablets. That too would solve the permanence problem. Anyone who wanted to verify the data could inspect the stone tablets to ensure that they had not been altered, just as archeologists inspect ancient steles today. But having computers write data to steles would make it difficult to copy and transfer that data even when the data has not been altered. Blockchain captures the unalterability of stone inscriptions without suffering from limits on communicability associated with the use of stone as a medium.
But why exactly does encryption breed permanence? Can’t you just crack the code and change the data in a way that respects the encryption format and therefore is not detectable by others? The answer is no because cracking codes is hard, requiring powerful computers, lots of electricity to run them, and time. Just as effectively rechiseling a stone inscription requires expertise, energy, and time. So blockchain uses encryption to restore the permanence in data that the information age destroyed.
With one important difference. Blockchain is an effective check on the undetected rewriting of data, as are steles, but, unlike steles, blockchain is no check on destruction of data, in the sense that blockchain makes deleting data from computer systems no harder to do than before. That is the price blockchain pays for allowing users to continue to communicate quickly with each other. Blockchain sits on top of the electron-based storage systems of computers, making it very hard to change the data undetected, but no harder to destroy the data on those systems. An electric shock will still suffice for that.
So the pharaohs still have something on computers, at least with respect to preventing data destruction, rather than just the alteration of data. (Of course, unlike data stored on steles, internet data is stored in multiple locations, forcing the destroyer to travel to be effective.)
Blockchain is so much an artifact of information technology that it could not be useful without that technology. The basic blockchain concept of using encryption to prevent alteration of data has been around forever. People wrote in code in the 16th century as much to keep their words secret as to ensure that what they did write could not be altered imperceptibly. But encoding and decoding are expensive and time intensive, even when you have the key to the code, and are not trying to crack it. Blockchain is feasible on a large scale only because users can rely on computers to determine whether data conforms to the required format. Thus information technology, despite feeding on impermanence, also enables a new kind of permanence.
The tearing down of constraints, so feted in our technological age, is not always a good thing. Nature is constraint. Technology, in mastering nature, removes constraint. But a lack of constraint is chaos, the opposite of civilization. One way to retain constraint is through law, but that has proven a feeble method. The only alternative is therefore to use technology to build artificial constraints back into nature, albeit in ways that are more suitable to our needs than natural constraints once were. Blockchain is an installment in that enterprise.
(I thank Thibault Schrepel and Sam Weinstein for piquing my interest in blockchain.)