From #blockchain to #BadgeChain (3) — the trustworthy chain

In the previous post we added to the Open Badges’ DNA its first genes extracted from the blockchain. We obtained the following results:

  • Everything can be represented as a Badge — everything is relationship;
  • A BadgeChain is made of chained badges (not yet a blockchain);
  • A BadgeChain is a distributed database: badges are stored all over the Internet.
  • New objects can grow organically from the aggregation of badges in the BadgeChain — e.g. ePortfolios.

There are two points we have not addressed yet:

  • How is the BadgeChain practically stored?
  • How can we trust the content of the BadgeChain?

The trustworthy BadgeChain

Can we check whether the components of the BadgeChain, a badge, is authentic (the issuer is the issuer, the earner is the earner, etc.) simply by looking at it, just as we would do to check whether a banknote is counterfeit? The answer is yes, and the means to do it is named cryptography. Here are the conditions to create badges that resist effective counterfeiting:

  • Every participant in the network uses one or more public / private key pair;
  • The public keys are used as the identities of the participants in the network.
  • The private keys are used to encrypt information that can then be deciphered using the matching public keys.
  • Reciprocally, the private keys are used to decipher any information encrypted by the matching public keys

The picture below illustrates the process when Alice creates a badge containing the information that will be used to verify whether it is authentic or not.

How to create trustworthy badges using cryptography?

What happens when Alice creates a badge:

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From #blockchain to #BadgeChain (2) – the chained badge

In the previous post, we looked at the relationship between trust, Open Badges and blockchains. To paraphrase George Bernard Shaw, one could say: Open Badges and blockchains are two technologies separated by a common idea [trust].

To explore how Open Badges and blockchains could merge into a new technical object, my reasoning will pass through several stages. We will start with a BadgeChain that does not make any reference to the blockchain technology, then, step by step, we will describe the mutation of this initial object through the incorporation of new genes into its DNA — hoping that we will not have created a chimera!

BadgeChain take one: everything is a badge

To create something that looks like a BadgeChain, we need to link badges together; there are multiple ways this can be achieved:

  • Indirectly: badges are “connected” through each individual issuer and earner. The issuer is a kind of “connector” between all the badges issued (and their earners), the earner is a kind of “connector” between all the badges received (and their issuers). Badges can also be connected through the alignment metadata, a list of objects describing educational standards — a property of the version 1.5 of the standard that has not been widely exploited.
  • Directly: badges are literally linked to other badges. For example, an endorsement badge could use the address of the badge being endorsed as the identification for the earner of that badge.

An Endorsement Badge as connected badge

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