---
title: authData
framework: applearchive
role: symbol
role_heading: Instance Property
path: applearchive/archiveencryptioncontext/authdata
---

# authData

An optional, unencrypted set of data that’s stored in the archive prologue.

## Declaration

```swift
var authData: Data? { get set }
```

## Discussion

Discussion Use this property, for example, to store a certificate chain for the archive signing entity. Note that the Apple Encrypted Archive format only transports this data and doesn’t interpret them. You can retrieve this data before you unlock the archive,

## See Also

### Getting and setting encryption context properties

- [decryptAttributes()](applearchive/archiveencryptioncontext/decryptattributes().md)
- [archiveIdentifier](applearchive/archiveencryptioncontext/archiveidentifier.md)
- [checksumMode](applearchive/archiveencryptioncontext/checksummode-swift.property.md)
- [ArchiveEncryptionContext.ChecksumMode](applearchive/archiveencryptioncontext/checksummode-swift.struct.md)
- [containerSize](applearchive/archiveencryptioncontext/containersize.md)
- [encryptionMode](applearchive/archiveencryptioncontext/encryptionmode-swift.property.md)
- [ArchiveEncryptionContext.EncryptionMode](applearchive/archiveencryptioncontext/encryptionmode-swift.struct.md)
- [compressionAlgorithm](applearchive/archiveencryptioncontext/compressionalgorithm.md)
- [ArchiveCompression](applearchive/archivecompression.md)
- [compressionBlockSize](applearchive/archiveencryptioncontext/compressionblocksize.md)
- [paddingSize](applearchive/archiveencryptioncontext/paddingsize.md)
- [profile](applearchive/archiveencryptioncontext/profile-swift.property.md)
- [ArchiveEncryptionContext.Profile](applearchive/archiveencryptioncontext/profile-swift.struct.md)
- [rawSize](applearchive/archiveencryptioncontext/rawsize.md)
- [signatureEncryptionKey](applearchive/archiveencryptioncontext/signatureencryptionkey.md)