Choose drive encryption method and cipher strength (Windows 8, Windows Server 2012, Windows 8.1, Windows Server 2012 R2, Windows 10 [Version 1507]): registry value EncryptionMethodNoDiffuserComputerHKLM\Software\Policies\Microsoft\FVE

Policy ID: EncryptionMethodNoDiffuser_Name
Scope: Computer Configuration
Supported on: At least Windows Server 2012, Windows 8 or Windows RT
Source: Administrative Templates (.admx) for Windows 11 2026 Update (26H2) (version 1.0)
Category: Windows Components › BitLocker Drive Encryption

Registry

EncryptionMethodNoDiffuser

REG_DWORDComputer

HKLM\SOFTWARE\Policies\Microsoft\FVE Current key

Enabled value: Depends on the option value
Element: Select the encryption method:

Options
Item	Stored value
AES 128-bit (default)	3
AES 256-bit	4

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\FVE]

; Options (use only one)
; AES 128-bit (default)
"EncryptionMethodNoDiffuser"=dword:00000003
; AES 256-bit
"EncryptionMethodNoDiffuser"=dword:00000004

CMD

:: Options (use only one)

:: AES 128-bit (default)
reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v "EncryptionMethodNoDiffuser" /t REG_DWORD /d 3 /f
:: AES 256-bit
reg add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v "EncryptionMethodNoDiffuser" /t REG_DWORD /d 4 /f

PowerShell

# Common: create the key
New-Item -Path 'HKLM:\SOFTWARE\Policies\Microsoft\FVE' -Force | Out-Null

# Options (use only one)
# AES 128-bit (default)
New-ItemProperty -Path 'HKLM:\SOFTWARE\Policies\Microsoft\FVE' -Name 'EncryptionMethodNoDiffuser' -PropertyType DWord -Value 3 -Force | Out-Null
# AES 256-bit
New-ItemProperty -Path 'HKLM:\SOFTWARE\Policies\Microsoft\FVE' -Name 'EncryptionMethodNoDiffuser' -PropertyType DWord -Value 4 -Force | Out-Null