Thursday, October 29, 2020

The Long Now

A talk by Stewart Brand and Danny Hillis about 25 years ago explaining the concept of the "Long Now" and the idea of building a 10,000-year clock to illustrate it was what started me thinking about long-term digital preservation. The idea of Lots Of Copies Keep Stuff Safe (LOCKSS), and the acronym came a couple of years later.

Hōryū-ji by Nekosuki, CC-BY-SA

Now, in The Data of Long-lived Institutions on the Long Now Foundation's blog, Alexander Rose refers to Hōryū-ji:
At about 1,400 years old, these are the two oldest continuously standing wooden structures in the world. And they’ve replaced a lot of parts of them. They keep the roofs on them, and even in a totally humid and raining environment, the central timbers of these buildings have stayed true. Interestingly, this temple was also the place where, over a thousand years ago, a Japanese princess had a vision that she needed to send a particular prayer out to the world to make sure that it survived into the future. And so she had, literally, a million wooden pagodas made with the prayer put inside them, and distributed these little pagodas as far and wide as she could. You can still buy these on eBay right now. It’s an early example of the philosophy of “Lots of Copies Keep Stuff Safe” (LOCKSS).
Below the fold, more on Rose's interesting post.

Tuesday, October 27, 2020

Unbanking The Banked

David Gerard has been writing a follow-up to his must-read and surprisingly successful Attack of the 50 Foot Blockchain: Bitcoin, Blockchain, Ethereum & Smart Contracts, entitled Libra Shrugged: How Facebook Tried to Take Over The Money. The Kindle version goes live on Amazon next Monday.

As one of his Patreons, I've been reading the chapters as he finished them. It isn't a laugh-a-minute read like his first book, but like the first it is a copiously sourced account of incredible hubris. Facebook's hubris led them to believe that they could, in effect, become a sovereign currency issuer like a government, without any of the responsibilities that governments assume when they control a currency. Actual governments looked at this proposal and responded "you have to be kidding". Follow me below the fold for more.

Tuesday, October 6, 2020

A Note On Blockchains

Blockchains have three components, a data structure, a set of replicas, and a consensus mechanism:
  • The data structure is often said to provide immutability or to be tamper-proof, but this is wrong. It is made out of bits, and bits can be changed or destroyed. What it actually provides is tamper-evidence, revealing that the data structure has changed.
  • If an unauthorized change to the data structure is detected the damage must be repaired. So there must be multiple replicas of the data structure to allow an undamaged replica to be copied to the damaged replica.
  • The role of the consensus mechanism is to authorize changes to the data structure, and prevent unauthorized changes. A change is authorized if the consensus of the replicas agrees to it.
Below the fold, some details.