The Blockchain promise
Blockchains are public ledgers that record events. Once data is in the blockchain, it can’t be changed. Blockchains can be decentralised, so that no single entity can change the blockchain without agreement of all other participants. Although blockchain technology was made famous by the popularity of cryptocurrencies like Bitcoin, the principles can be leveraged by anything that requires an immutable record, for example a machine’s daily activity, a birth certificate or a property transaction.
Self-Sovereign Identity (SSI)
A real-world application of blockchain that we are particularly passionate about is Self-Sovereign Identity (SSI). With SSI, a decentralised blockchain is used to record cryptographic public keys and information on how to reach the participants. SSI leverages blockchains to stay secure and is decentralised to preserve user privacy.
When it it useful to use SSI?
Through SSI, we can enable simple yet powerful identity use cases. We have listed an example:
- A university registers to an SSI system, placing their public keys in the blockchain.
- Other participants cryptographically agree that this is the university – this is now a fact that cannot be removed from the blockchain.
- The university issues a degree certificate in the form of a credential to a student, which is digitally signed. The signature can be verified with the university’s public key – the one that is in the blockchain and that everyone else has vouched for.
- The student sends the credential to a potential employer.
- The employer gets the university’s public key from the blockchain, confident that it is the correct key, as agreed in the past and cryptographically proven to not have been changed. This would even work if the university no longer exists.
- The potential employer can verify the credential and confirm that the student has a degree from the university.
- The above can be repeated for every potential employer the student applies at, without the need to send multiple copies of a paper degree.
- The university has no way to know to which employer the student has applied to; the graduate’s privacy is preserved.