---
title: Change history for device security (Windows 10)
description: This topic lists new and updated topics in the Windows 10 device security documentation for Windows 10 and Windows 10 Mobile.
ms.prod: w10
ms.mktglfcycl: deploy
ms.sitesec: library
ms.pagetype: security
author: brianlic-msft
---

# Change history for device security
This topic lists new and updated topics in the [Device security](index.md) documentation.

## September 2017
|New or changed topic |Description |
|---------------------|------------|
| [TPM fundamentals](tpm/tpm-fundamentals.md)<br>[BitLocker Group Policy settings](bitlocker/bitlocker-group-policy-settings.md) | Explained the change to allow reducing the maximum PIN length from 6 characters to 4. |


## August 2017
|New or changed topic |Description |
|---------------------|------------|
| [BitLocker: Management recommendations for enterprises](bitlocker/bitlocker-management-for-enterprises.md) | New BitLocker security topic. |
| [Accounts: Block Microsoft accounts](security-policy-settings/accounts-block-microsoft-accounts.md) | Revised description |


## July 2017
|New or changed topic |Description |
|---------------------|------------|
| [How Windows 10 uses the Trusted Platform Module](tpm/how-windows-uses-the-tpm.md) | New TPM security topic. |


## May 2017
|New or changed topic |Description |
|---------------------|------------|
| [BitLocker Group Policy settings](bitlocker/bitlocker-group-policy-settings.md) | Changed startup PIN minimun length from 4 to 6. |
| [Network access: Restrict clients allowed to make remote calls to SAM](security-policy-settings/network-access-restrict-clients-allowed-to-make-remote-sam-calls.md) | New security policy setting. |

## March 2017
|New or changed topic |Description |
|---------------------|------------|
|[Requirements and deployment planning guidelines for Device Guard](device-guard/requirements-and-deployment-planning-guidelines-for-device-guard.md) | Updated to include additional security qualifications starting with Windows 10, version 1703.|