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# ENTemporaryExposureKey

The key used to generate rolling proximity identifiers.

```
class ENTemporaryExposureKey
```

## Overview> Important:
> This class is available in iOS 12.5, and in iOS 13.5 and later.

Upon a positive diagnosis, the user is allowed to submit their temporary exposure keys to their Health Authority server as diagnosis keys. Use [`getDiagnosisKeys(completionHandler:)`](/documentation/ExposureNotification/ENManager/getDiagnosisKeys(completionHandler:)) to obtain the user’s diagnosis keys for submission.

## Topics

### Exposure Criteria

[`var transmissionRiskLevel: ENRiskLevel`](/documentation/ExposureNotification/ENTemporaryExposureKey/transmissionRiskLevel)

The risk of transmission associated with the person a key came from.

[`var rollingPeriod: ENIntervalNumber`](/documentation/ExposureNotification/ENTemporaryExposureKey/rollingPeriod)

The length of time that this key is valid.

[`var keyData: Data`](/documentation/ExposureNotification/ENTemporaryExposureKey/keyData)

The temporary exposure key information.

[`var rollingStartNumber: ENIntervalNumber`](/documentation/ExposureNotification/ENTemporaryExposureKey/rollingStartNumber)

A number that indicates when a key’s rolling period started.

[`typealias ENIntervalNumber`](/documentation/ExposureNotification/ENIntervalNumber)

A number assigned to each 10-minute window shared between all devices participating in the protocol.

## Relationships

### Conforms To

[`Equatable`](/documentation/Swift/Equatable)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`Hashable`](/documentation/Swift/Hashable)

[`CVarArg`](/documentation/Swift/CVarArg)

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

### Inherits From

[`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class)

---

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