August 30, 2021

What is Self-Sovereign Identity and how does it work?

Who are you? Who decides if you are really you? Can you be trusted? And where does peaq fit in?

We currently live within the realms of two separate, yet intertwined worlds. They are the physical and the digital, and to accept the latter is necessary to survive within the 21st Century. Much of our identification is represented in physical form, and to many this is somewhat comforting. We can carry ID cards in our wallets, keep birth certificates in safes, and can hold in our hands the original and certified document. Whether they are organized neatly into a folder or thrown into the compartment known as “the drawer,” we have grown up with being able to touch our identity.

'The drawer' is now consigned to history

But the physical world is not keeping pace with the digital one, and even less so with the pandemic forcing millions to work, consume, and socialize remotely from home. People are also getting frustrated with the bureaucracy that comes with paper documents, contracts, and ID, and rightly so. The solution comes in the form of Self-Sovereign Identities (SSI). The last thing anyone needs is another acronym, but this article will help you navigate this technology, and its many technicalities, to prove why it’s worth the effort to acclimatize yourself to it. 

The name says it all; to give you autonomy over your documents of identification.

The main principle behind SSIs is that identity information such as birth certificates, Driver’s Licenses, University Degrees, and other things in “the drawer” should be more easily accessible, secure and private in the digital world as it is in the physical world. Many digital services for identity and signing documents already exist. However, SSIs are causing a buzz because they give the user autonomy. Your data is not controlled by a host. It is not controlled by a server set up by a third party. You have sovereignty over the documents you choose to digitize. 

SSIs can be broken down into three components. Each offers individual benefits that combine to ensure that people are provided with easy access to, and security for, their identification documents.

Verifiable Credentials

These are statements about the holder (which could be you, your company, or your machine) that are assigned by ‘issuers.’ Issuers are trustworthy people, or institutions who provide the holder with verifiable credentials which they sign with their SSIs. What’s beneficial is that you can prove something without sending all the information, just what’s needed. For instance, if you are required to verify your age via a Driver’s License but are hesitant to give away the address on it, you can do so and do so automatically. This links into another facet of Verifiable Credentials known as Zero-Knowledge Proof (ZKP), allowing holders to prove something in a document without revealing the complete information.

Confused? Don’t be. Let us stick with the example of a Driver’s License. An SSI may allow you to prove that you are over the age of 18 but do not need to give out your date of birth. This feature allows you to choose what information you share, with whom, and when. 

Decentralized Identifiers (DIDs)

DIDs create unique, private, and secure peer-to-peer connections between two people or things. You know who you are connecting with and vice versa. Nobody else can interfere in any way. DIDs are crucial to understand because they are the crux of why SSIs are earning their revolutionary stature. They provide a public key (the identity of the person) and simultaneously a private key with which to sign any identification document. 

The best way to explain the value comes from our over-reliance on intermediaries such as Google and Facebook when sharing information. The metadata gathered from our interactions online is mostly out of our control, and big tech can barrage you with targeted advertisements from interactions you have on their platforms. It’s an inconvenience at best, but when it comes down to the more important information you share, the problem becomes more menacing.

DIDs ensure that the Verifiable Credentials you have can only be shared with people or things you deem trustworthy. So now you have the necessary documents, you have the secured connections, the last part is how blockchain brings it all together.


Within the context of SSIs, blockchains serve a vital function in ensuring that everyone in the network has the same source of the truth. They ensure that each transaction, purchase, or movement of a document can be easily checked via a sort of digital paper trail. The cost or effort of corrupting a record would be so great as to make it more or less impossible. Using the blockchain, and its trail of evidence and authentication, anyone can be reassured that a document is correct given that they can also check who ‘validated’ you, e.g., a government agency.

Recap of the three elements

  • Verifiable Credentials allow you to select the information you wish to disclose. With a Driver’s License, you can use it to prove your age without having to provide your full date of birth.
  • Decentralized Identifiers create secure and private connections between you and the other entity you wish to share your data with. 
  • Blockchain is the backbone. Everyone on the network has access to the same source of information. Everyone knows where they stand and verifying the validity of any document can be done independently. 

Real-life example
Imagine that you are working in a company that wishes to provide refugees with work. Doing so will mean that work permits are needed, and this involves a very lengthy, paper-based process in the physical world. Therefore, it would be in everyone’s interest to interact with SSIs. With them you can verify the identification documents of potential employees and provide a digital, cryptographic proof attesting that you have a registered business and are thus eligible to be given work permits by the government. What would typically take weeks, if not months, could be dramatically reduced.

Machines with identities – onto the next chapter
Interoperability, portability, and speed make SSIs critical to understand within the current global climate, and peaq is firmly playing its part within the vanguard. We are already working to ensure that such technology can make the digital world less of a headache than the physical one we occupy.

At peaq, we’re giving things - i.e vehicles, machines and devices -their own unique, Self-Sovereign Identities. Our things are rapidly becoming extensions of ourselves. In giving them their own secure digital identities we're on the one hand ensuring the same levels of security and privacy of information for our things as we are for ourselves, and on the other hand we're giving things the ability to independently provide services to other people on our behalf. More on this in our next article on SSIs.

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