# Credential

A `Credential` entry represents a [credential](/es-es/docs/concepts/decentralized-storage/credentials), which contains an attestation about a *subject* account from a *credential issuer* account. The meaning of the attestation is defined by the issuer.

Credentials
## Example Credential JSON


```json
{
    "LedgerEntryType": "Credential",
    "Flags": 65536,
    "Subject": "rsUiUMpnrgxQp24dJYZDhmV4bE3aBtQyt8",
    "Issuer": "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX",
    "IssuerNode": "0000000000000000",
    "CredentialType": "6D795F63726564656E7469616C",
    "PreviousTxnID": "8089451B193AAD110ACED3D62BE79BB523658545E6EE8B7BB0BE573FED9BCBFB",
    "PreviousTxnLgrSeq": 234644,
    "SubjectNode": "0000000000000000",
    "index": "A738A1E6E8505E1FC77BBB9FEF84FF9A9C609F2739E0F9573CDD6367100A0AA9"
}
```

## Credential Fields

In addition to the [common fields](/es-es/docs/references/protocol/ledger-data/common-fields),  entries have the following fields:

| Field | JSON Type | [Internal Type](/docs/references/protocol/binary-format) | Required? | Description |
|  --- | --- | --- | --- | --- |
| `CredentialType` | String - Hexadecimal | Blob | Yes | Arbitrary data defining the type of credential this entry represents. The minimum length is 1 byte and the maximum length is 64 bytes. |
| `Expiration` | Number | UInt32 | No | Time after which the credential is expired, in [seconds since the Ripple Epoch](/docs/references/protocol/data-types/basic-data-types#specifying-time). |
| `Issuer` | String - [Address](/docs/references/protocol/data-types/basic-data-types#addresses) | AccountID | Yes | The account that issued this credential. |
| `IssuerNode` | String | UInt64 | Yes | A hint indicating which page of the issuer's directory links to this entry, in case the directory consists of multiple pages. |
| `PreviousTxnID` | String - [Hash](/docs/references/protocol/data-types/basic-data-types#hashes) | UInt256 | Yes | The identifying hash of the transaction that most recently modified this entry. |
| `PreviousTxnLgrSeq` | Number | UInt32 | Yes | The [index of the ledger](/docs/references/protocol/data-types/basic-data-types#ledger-index) that contains the transaction that most recently modified this entry. |
| `Subject` | String - [Address](/docs/references/protocol/data-types/basic-data-types#addresses) | AccountID | Yes | The account that this credential is for. |
| `SubjectNode` | String | UInt64 | Yes | A hint indicating which page of the subject's owner directory links to this entry, in case the directory consists of multiple pages. |
| `URI` | String - Hexadecimal | Blob | No | Arbitrary additional data about the credential, for example a URL where a W3C-formatted Verifiable Credential can be retrieved. |


## Credential Flags

Credential entries can have the following flags combined in the `Flags` field:

| Flag Name | Hex Value | Decimal Value | Description |
|  --- | --- | --- | --- |
| `lsfAccepted` | `0x00010000` | 65536 | If enabled, the subject of the credential has accepted the credential. Otherwise, the issuer created the credential but the subject has not yet accepted it, meaning it is not yet valid. |


## Credential Reserve

A credential entry counts as one item towards the owner reserve of the subject account, if the subject has accepted the credential. Otherwise, a credential entry counts as one item toward the reserve of the issuer account.

## Credential ID Format

The unique ID of a Credential entry is the SHA-512Half hash of the following values concatenated in order:

* The `Credential` space key (`0x0044`);
* The `Subject` field's value;
* The `Issuer` field's value; and
* The `CredentialType` field's value.


## See Also

- **Transactions:**
  - [CredentialAccept transaction](/docs/references/protocol/transactions/types/credentialaccept)
  - [CredentialCreate transaction](/docs/references/protocol/transactions/types/credentialcreate)
  - [CredentialDelete transaction](/docs/references/protocol/transactions/types/credentialdelete)