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: