# Verifiable Credentials

The one drawback to fully decentralized verification system like DIDs is that it lacks the security that centralized can bring verification brings. To solve this, [Verifiable Credentials](https://www.w3.org/TR/vc-data-model/)(VC) will be added to DIDs.

Credentials are part of every person's daily life in society. We use credentials such as driver's licenses to show we are legally able to operate a motor vehicle, and for identification purposes when register to vote, fly domestically, and when signing up for Know Your Customer(KYC) verification services. Credentials also used for various membership cards for government services like community pool passes, library cards, and fishing permits. These credentials provide a way for people in society to verify who someone is and to ensure they have the proper authority to do something

[Verified Credentials](https://www.w3.org/TR/vc-data-model/) are digital credentials that act as digital counterparts to physical credentials. They store all data digitally that a normal credential would. 

#### Example Credential information

* Personal Identifying Information(photo, name, DOB, physical attributes)
* The Issuing Authority(governmental body, organization, company, etc)
* Credential Type(Goverment issued licenses, passport, library card, etc)
* Unique Identifier(license ID, employee ID, SSN, etc)
* Evidence to how this credential was derived
* Credential restraints(expiration date, credential uses and restrictions)

VCs can contain additional data for technologies that can digital sign VCs and that can also enable safeguards against fraudulent credentials. Also, Unlike normal credentials, VCs can be transmitted rapidly allowing for instant use across the web.

## How Do VCs authenticate

<figure><img src="/files/mihFoziUrH5wbmr6NsEP" alt=""><figcaption><p>VC authorization flow</p></figcaption></figure>

[**Holder**](https://www.w3.org/TR/vc-data-model/#dfn-holders): A role an entity may take when processing one or more VC and when generating a [verifiable presentation](https://www.w3.org/TR/vc-data-model/#dfn-verifiable-presentations). &#x20;

[**Issuer**](https://www.w3.org/TR/vc-data-model/#dfn-issuers): An entity that transmits VCs to a holder. Examples: government bodies, corporations, member clubs, and more.

[**Subject**](https://www.w3.org/TR/vc-data-model/#dfn-subjects)**:** An entity a claim(a request for a VC) is made about. In most cases the Holder is also the Subject, however in some cases a holder may hold VCs for other subjects. An example of this would be a parent holding VCs representing their children's passports or SSNs.

[**Verifier**](https://www.w3.org/TR/vc-data-model/#dfn-verifier): An entity requesting the processing of a VC. Examples: TSA agents at airports, employers, security personal, and online services.

[**Verifiable Data Registry**](https://www.w3.org/TR/vc-data-model/#dfn-verifiable-data-registries)**:** A system responsible for the creation and verifications of all VC related data. Registries can provide any data need to process VCs and create [verifiable presentations](https://www.w3.org/TR/vc-data-model/#dfn-verifiable-presentations).

[**Verifiable Presentations**](https://www.w3.org/TR/vc-data-model/#dfn-verifiable-presentations)**:** A tamper-evident presentation that is encoded so the authorship of the data can be verified cryptographically. Not all Verifiable Presentaions will include all data from VCs, but may choose to include data derived from VCs.&#x20;


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