Forum Discussion
Bitlocker PIN
Hello, I would like to know what your Bitlocker PIN policies are and how you approach them.
Do you use a PIN that consists only of numbers, or a PIN that allows the use of characters such as upper and lower case letters, symbols, numbers, and spaces?
I am asking this from the perspective of “user acceptance,” but also as an additional layer of device security.
Hy,
I conclude after inspecting this that every company needs to decide what works best when it comes to PIN length and complexity. Microsoft provides flexible options and best practices that help balance security and user convenience.
That being said, this gives organizations the flexibility to customize their PIN policies to align with their unique security requirements and operational needs.
I’m reposting the link along with the planning guide for your reference:
4 Replies
Hy,
I conclude after inspecting this that every company needs to decide what works best when it comes to PIN length and complexity. Microsoft provides flexible options and best practices that help balance security and user convenience.
That being said, this gives organizations the flexibility to customize their PIN policies to align with their unique security requirements and operational needs.
I’m reposting the link along with the planning guide for your reference:
Hello,
Thank you for raising this critical point. Our approach to BitLocker PIN policies balances security strength with user acceptance:
- PIN Composition
- We enforce a numeric PIN for pre-boot authentication. This is the Microsoft-recommended baseline and ensures broad compatibility with devices, especially during startup before full keyboard driver’s load.
- Length Requirement
- To strengthen numeric PINs, we require a minimum length of 8 digits (and allow longer). This significantly raises entropy while still being user-friendly.
- Non-Numeric Options
- BitLocker does support alphanumeric PINs (upper/lower case, symbols, spaces). However, we avoid enforcing these because:
- Not all pre-boot environments handle special characters consistently.
- It increases complexity for users and can reduce acceptance.
- Additional Safeguards
- PINs are combined with TPM protection, so even with numeric PINs the security is strong.
- Device policies enforce lockout thresholds to mitigate brute-force attempts.
- Recovery keys are centrally escrowed in Azure AD / Intune for compliance.
Our Policy Rationale
- Security: TPM + minimum 8-digit numeric PIN provides sufficient resistance to offline attacks.
- Usability: Numeric PINs are easy to type on any keyboard layout and less error-prone for users.
- Scalability: Consistent policy across the fleet reduces helpdesk issues and enrolment failures.
In summary, we use numeric-only PINs with a defined minimum length, prioritizing compatibility and adoption, while still leveraging TPM and lockout protections for strong device security.
You could something like NIST standards.
According to NIST minimum 6 characters for the PIN and no complexity rules required and PIN can be digital only.
thx, the NIST recommendations are a little bit to old (2010), or I was checking the wrong official Link.
But Microsoft have a strong recommendation regarding this:
The challenge with setting a minimum PIN length of 6 digits is that it allows for simple PINs, like those used for Windows Hello, which are not very secure. Conversely, increasing PIN complexity—for example, requiring alphanumeric characters—forces end users to remember multiple passwords, which can be inconvenient.
So, this requires further consideration. I will review the details and provide a formal statement later
Good luck!
