---
title: attrSmimeMSEncryptionKeyPrefs
framework: security
role: symbol
role_heading: Type Property
path: security/cmssignedattributes/attrsmimemsencryptionkeyprefs
---

# attrSmimeMSEncryptionKeyPrefs

Indicate that the signing certificate included with the message is the preferred one for S/MIME encryption, but using an attribute object identifier (OID) preferred by Microsoft.

## Declaration

```swift
static var attrSmimeMSEncryptionKeyPrefs: CMSSignedAttributes { get }
```