A pixel of Azra Aksamija’s Memory Matrix, with associated bitcoin address, see the corresponding transaction here.

Recently I have been working on the idea of cryptographic heritage: How to use Bitcoin and blockchain technology to store evidence of material and immaterial cultural heritage under threat in ethnic and nationalistic conflicts. This idea is inspired by the work of the artist and architecture historian Azra Aksamjia, who has worked extensively on the role of architecture and cultural heritage in the Balkan wars and the current conflicts in the Middle East.

To give an example — in nationalistic conflicts, cultural heritage such as libraries, religious buildings, or historic monuments are the first things targeted for destruction. This is because they bear testimony of a multicultural past, as Aksamija has demonstrated in her analysis of the Balkan wars of the 90s. These efforts included denial that a particular community has been living in an area before ethnic cleansing — to the extent that buildings are erased not only from the city, but also from old postcards and archival material. Needless to say, this also has implications for ownership of land and houses of the displaced.

UNESCO and other entities tried to address this by capturing immaterial cultural heritage through databases and websites. The problem is that these websites are just as vulnerable as the practices and buildings they are supposed to document.

Here is where Bitcoin comes into the picture. There has been a lot of talk about its possibilities as a global currency or about applications of its underlying blockchain technology. Its most obvious advantage, offering a versatile suite of cryptographic tools and a distributed, tamper-proof database for everyone to use, is however rarely mentioned. Verify authenticity of documents, securely sign messages, insert indeletable and immutable information in a globally distributed database are just a few examples of this.

Imagine if a community could prove, verifiable for everyone, that it lived at a certain time in a certain place; documenting its landmarks, properties, and practices. Residents could publicly declare “this is my house” and provide evidence that nobody can hide or delete after displacement and ethnic cleansing.

So far the high level idea. On the practical level it is still difficult and controversial to record non-financial information in the blockchain, which is a limited resource that already has a spam problem. There are several methods, each with its own advantages and drawbacks:

Using a bitcoin transaction as a signature for an external document. The most common way, this is how bitcoin is intended to work. The blockchain becomes a method of notarizing a document. This has the problem that the external document, online or offline, can still get destroyed. Writing text directly into the block chain, either in the block header (through the miners) or encoded in the address. The former is limited and expensive, the latter robust, but inelegant and bloats the system. Attaching an OP_RETURN diagnostic message which is also stored in the blockchain, but still involves some uncertainties of how this data will be handled in the future. So far, this seems to be the most promising approach, as it is directly supported by the Bitcoin protocol. See how this works in practice here.

Azra Aksamija’s Memory Matrix, a “living monument raising awareness about the destruction of cultural heritage in the Middle East”

The idea of cryptographic heritage is at the moment tested in Azra Aksamija’s Memory Matrix project, which recreates destroyed heritage on MIT campus in a participatory project. Individual plexiglass jewelry, arranged as pixels to form the destroyed arch of Palmyra, are inscribed with the cultural memory of individual participants, and are also encoded with a message in the blockchain that only the original author has control over.

The owner of a pixel can prove ownership of the jewelry through the associated private key, can use the key to sign and authenticate messages. Also the public can use the public key to encrypt messages that only the owner can decode.

Victims of ethnic cleansing often keep the keys to the front door of their former home from which they were expelled as a memento. See the recent documentary project by photographer Bradley Secker.

With cryptographic heritage, the key is no longer a symbolic item, it can store value, prove ownership, transmit messages, and leave a mark and testimony in the world.*

You have to go to the link to see the striking photographs, I did not want to hotlink copyrighted material

Update: the ideas elaborated above may seem like an appropriation of Bitcoin and the blockchain rather than an application. I emphasized cryptography and persistent storage over the transaction, the basic function of Bitcoin as a currency. I wanted to avoid the impression of a transactionalization of cultural heritage, a one-to-one translation into digital cash. However, there are also interesting parallels to how traditional currencies are used to formalize relationships and contracts. Consider someone selling property to a foundation for a symbolic value of $1. The purpose of such a transaction is not the exchange of a nominal value, but to formalize a relationship, establish a contract and enter it into the public record. A symbolic payment is a commitment, and making a transaction can be a performance that establishes a contract.

*(assuming that bitcoin will still be around in 10 years, who knows….)

Edit: brilliant Giulio Quaggiotto of NESTA did work on the blockchain in development — check it out