July 3, 2025 • Mary Marshall

NIST 800-63 Digital Identity Guidelines: Mastering IAL, AAL, and FAL for Enterprise Security

Implement NIST 800-63 identity assurance levels (IAL/AAL/FAL) with Avatier’s comprehensive identity management solutions.

The NIST Special Publication 800-63 provides comprehensive digital identity guidelines that create critical frameworks for identity proofing, authentication, and federation. For organizations committed to robust security and regulatory compliance, understanding and implementing these standards—particularly the NIST 800-63 identity assurance levels (IAL), authentication assurance levels (AAL), and federation assurance levels (FAL)—is essential.

1. Identity Assurance Levels (IAL)

IAL is all about proofing.

  • IAL‑1 – just a username and maybe an email. No real check that “John Doe” is actually John. Small coffee shops sometimes stay at this level because they only need a way to send receipts.
  • IAL‑2 – you need to show a government ID or something that an agency can verify. My cousin Sara got her bank account upgraded after scanning a driver’s licence with her phone. The bank checked the photo against a state database.
  • IAL‑3 – the highest bar. You have to walk into a office, hand over the card, and get a staff member to look at it. Hospitals often demand this when a doctor accesses patient charts.

Research (Gartner) says companies that pick the right IAL see about 40 % fewer identity scams. That may mean they’re not over‑locking users who don’t need it.

But IAL can feel like a roadblock. Imagine a freelance graphic designer trying to sign up for a new client portal and being asked to show up in person for IAL‑3 – it could drive them away. So there’s a trade‑off: security versus friction.

2. Authentication Assurance Levels (AAL)

AAL asks “Is the login really the right person?”

  • AAL‑1 – one factor, usually a password. Easy but easy to guess.
  • AAL‑2 – two factors. You might type your password and then tap a code on your phone. My roommate Jake uses this for his school email and swears it stopped the spam attacks he used to get.
  • AAL‑3 – hardware keys or strong cryptography. Think of a tiny USB stick that you have to plug in. It stops phishing pretty much entirely, but you have to carry it around.

The NIST doc appears to push AAL‑2 as the sweet spot for most businesses. Still, some smaller firms skip MFA because they think customers will get annoyed.

3. Federation Assurance Levels (FAL)

FAL is the backstage pass when two companies share identity info.

  • FAL‑1 – basic bearer tokens, kind of like a paper ticket.
  • FAL‑2 – tokens signed with approved crypto – a little safer.
  • FAL‑3 – holder‑of‑key tokens that prove the holder actually owns the key. Big banks often demand this when they let partners see account data.

If you’re a city government linking its citizen portal to a state health system, you probably need at least FAL‑2.

How Avatier Fits In (and Where It Might Miss)

Avatier markets itself as an “all‑in‑one” identity platform that covers IAL, AAL and FAL. Below are some ways it can be useful – and some cautions.

Identity Proofing (IAL)

Avatier’s workflow lets you set up risk‑based checks. For a retail chain they offer automated ID scans that talk to DMV databases (good for IAL‑2). They also have a biometric add‑on for IAL‑3.

But the UI sometimes feels like a PowerPoint slide with too many boxes. A small business owner might spend more time clicking than actually verifying users.

Multi‑Factor Auth (AAL)

The product supports passwords, OTPs, FIDO2 keys and even facial recognition. In one pilot my friend Carlos ran at his tech startup, they switched from SMS codes to hardware tokens and saw a sharp drop in login failures.

Nevertheless, Avatier still lists “SMS allowed” as an option, even though NIST warns against it for higher AALs. That could confuse admins who just copy‑paste the default settings.

Federation (FAL)

Avatier supports SAML, OpenID Connect and OAuth out of the box. A local university used their SSO bridge to let students log into library services without new passwords.

Still, the documentation on holder‑of‑key (FAL‑3) is thin. If you really need the strongest federation you might have to call support three times before getting a clear answer.

Real‑World Hiccups

  1. User Experience vs Security: When my aunt tried to enroll in a government benefits site that required IAL‑3, she had to drive two hours to the local office just for a photo check. She complained that the whole process felt “like an obstacle course.” Companies need progressive security: only ask for the highest proof when the data is truly sensitive.
  2. Legacy Systems Hold Us Back: A midsize insurance firm tried to attach Avatier’s MFA to an old insurance‑policy app built in 2004. The connector kept timing out and the team ended up writing a custom script. That cost weeks of work and extra budget.
  3. Operational Overhead: Every month the compliance team at a regional bank runs a manual audit of who has which AAL level. Avatier’s dashboard can show the status, but the export formats are not friendly for their Excel‑loving auditors. So they still do half the work by hand.

Industry Snapshots

  • Government – Agencies often go straight to IAL‑3 and AAL‑3 because law says so. Avatier’s on‑premise option helps meet FIPS rules, but the cost can be high for smaller counties.
  • Healthcare – Hospitals pair IAL‑2 proofing with biometric fingerprint scans for doctors. They also need HIPAA and NIST alignment; Avatier’s “HIPAA ready” tag sounds reassuring but you still need a legal review.
  • Finance – Banks love FAL‑3 for inter‑bank data exchange. Avatier’s support for holder‑of‑key claims is useful, yet the product sometimes lags behind the newest banking standards like ISO 20022.

Small Tips for Getting It Right

  • Start with a risk map – Write down which apps hold personal data, which hold money, which just hold usernames. Then pick IAL/AAL/FAL accordingly.
  • Document everything – Even if you think a policy is obvious, write it down. Auditors love checklists.
  • Use progressive security – Show a user a password screen first; only prompt for MFA if they’re trying to access payroll data.
  • Teach the users – People often ignore MFA because they think it’s a hassle. A quick video from your IT lead can change that mindset.
  • Test often – Run phishing simulations once a quarter; see if AAL‑2 holds up against new tricks.
  • Stay updated – NIST releases revisions every few years. Set a calendar reminder to review the latest draft.

A Bit of Critique

While Avatier does bundle many pieces together, it sometimes feels like trying to fit a Swiss army knife into a pocket that’s already full of other tools. Some businesses might be better off picking separate specialist tools for proofing and for MFA rather than forcing everything into one platform. Also, the “one‑size‑fits‑all” language can mislead smaller firms into thinking they need all three assurance levels for every app, which would just drown them in friction.

In Conclusion

NIST 800‑63 gives us a map for building trust on the internet: know who people say they are (IAL), make sure they really are who they claim (AAL), and let other trusted parties accept that proof (FAL). The guidelines might mean you don’t have to lock every system at the highest level – just match the risk.

Avatier offers a convenient toolbox that can cover most of the map, but it isn’t flawless. Companies should weigh the ease of a single platform against possible complexity, cost and user pushback.

If you’re an IT manager at a midsize firm or a security officer at a hospital, start small: pick one critical app, decide its IAL/AAL/FAL needs, test Avatier’s features there, and learn from any hiccups before rolling out wider. By staying flexible, keeping users in mind and checking NIST updates regularly, you can turn those dense guidelines into everyday security that actually works—not just on paper.

That’s how we can make digital identity both safe and usable.

Try Avatier Today

Mary Marshall

NIST 800-63 Digital Identity Guidelines - Avatier