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# init(first:second:)

Initializes an assertion output structure with one or two keys.

```
init(first: SymmetricKey, second: SymmetricKey?)
```

## Parameters

`first`

A symmetric key that’s unique to the passkey and derives from the first input.

`second`

A second symmetric key that’s unique to the passkey, and derives from the second input, if specified.

---

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