---
title: kSecAttrSerialNumber
framework: security
role: symbol
role_heading: Global Variable
path: security/ksecattrserialnumber
---

# kSecAttrSerialNumber

A key whose value indicates the item’s serial number.

## Declaration

```swift
let kSecAttrSerialNumber: CFString
```

## Discussion

Discussion The corresponding value is of type CFData and contains the serial number data of a certificate. Items of class kSecClassCertificate have this attribute. Read only.