This is the 2nd in a short FHE 101 series. Check out the first article if you haven’t already.
Last time, we talked about Fully Homomorphic Encryption (FHE) and the strange idea that you can compute on encrypted data without ever decrypting it.
That usually leads to the next question:
“Wait… don’t we already encrypt everything?”
Fair question.
We talk about encryption constantly.
Banks use it.
Hospitals use it.
Cloud providers definitely put it on slide decks.
You’ve probably heard phrases like:
- encrypted at rest
- encrypted in transit
- AES-256
- TLS
- end-to-end encryption
It sounds comprehensive.
And to be fair, most of it is.
But there’s an important distinction hiding underneath all of it:
Traditional encryption only protects data at rest and in transit.
FHE protects data during computation.
That’s the difference.
And it matters more than you might think.
The Encryption You Already Know
First, the Acronyms We Pretend Everyone Understands
Security people love acronyms.
Sometimes I think half of cybersecurity is just confidently saying letters in meetings and hoping no one asks follow-up questions.
TLS
AES
RSA
PKI
At some point, we all collectively agreed to nod and move on.
So let’s slow that down for a second.
Because these aren’t magic—they’re just tools solving different problems.
And importantly:
None of them were designed to let you compute on encrypted data.
That part comes later.
TLS: Transport Layer Security
TLS stands for Transport Layer Security, which sounds like something invented by a committee, and it was.
This is the thing behind the little lock icon in your browser.
When you log into your bank, check your email, send a message, or buy something online, TLS is usually working in the background.
For example:
Your laptop sends login credentials to a bank’s server.
Without protection, that information is just moving across networks hoping everyone behaves.
TLS steps in and says:
Let’s not do that.
Its job is simple:
Make sure your data gets from point A to point B
without someone reading it in the middle.
Think of it like armored transport for information.
Your laptop to the bank’s website
Your phone to a web application
One cloud service to another
The package gets there safely.
Then somebody has to open it.
AES: Advanced Encryption Standard
AES stands for Advanced Encryption Standard, which somehow sounds both extremely important and incredibly boring.
It’s one of the most widely used encryption standards in the world.
TLS, as it turns out, is just AES under the hood. “The hood” is where the acronym PKI joins the conversation. We’ll save those details for another post.
AES protects data sitting still:
- files
- databases
- backups
- disks
- cloud storage
For example:
Your bank stores your account records in a database.
Your hospital stores patient records.
Your laptop stores files you forgot were on your desktop.
That information isn’t moving, it’s just sitting there.
AES helps make sure that if someone steals the drive, gains unauthorized access, or your laptop decides to go missing in an airport, they can’t simply open everything like it’s a folder labeled “definitely not important.”
Basically, if your laptop gets stolen and your week gets worse, AES is one of the reasons it hopefully doesn’t get much worse.
It’s secure storage.
The package is locked in the warehouse.
The Part in the Middle
Now for the awkward bit.
At some point, someone has to open the package.
Because if you want to:
- calculate a balance
- generate a dashboard
- run fraud detection
- train a model
- recommend what movie I should apparently watch next
…the system has to use the data.
Which means:
- TLS hands it over safely.
- AES stores it safely.
- And then someone opens it.
That moment—when data becomes usable—is also when it becomes vulnerable.
That’s the part most security diagrams politely speed past.
FHE Is Different
FHE doesn’t replace TLS or AES.
It solves a different problem.
Instead of asking:
“How do we protect data while moving or storing it?”
FHE asks:
“How do we protect data while using it?”
That’s a much harder question.
Because encrypted data is supposed to be unreadable nonsense.
And computers are famously bad at working with nonsense.
FHE changes that.
It allows computation to happen without removing the lock.
Which is either a breakthrough in cryptography…
or something that sounds like it should violate several laws of physics.
Mostly the first one.
Why This Isn’t “Better AES”
This is an important distinction.
FHE isn’t “AES, but stronger.”
It’s not version 2.0.
It’s a fundamentally different model.
AES says:
“Keep this safe until I need it.”
FHE says:
“What if you never had to expose it at all?”
That shift changes architecture, trust, and what becomes possible.
Not just security posture.
Real-World Example
Imagine a hospital wants to run analytics across sensitive patient data.
Today:
- encrypt the records
- store them securely
- decrypt them for analysis
- trust the environment doing the work
With FHE:
- encrypt the records
- run the analysis while they stay encrypted
- only the result gets decrypted by the owner
Same goal.
Very different trust model.
Much smaller “please don’t leak this” surface.
So Why Don’t We Use FHE Everywhere?
Because TLS and AES are fast, mature, and everywhere.
FHE is… not that.
At least not yet.
It’s heavier.
Slower.
More complex.
That “yet” matters.
A big part of what’s changing is the combination of purpose-built hardware and platforms designed specifically for encrypted computation.
At Niobium, we’re building both.
On the hardware side, we’re developing a custom ASIC, purpose-built silicon designed for FHE workloads, because general-purpose compute can only take you so far.
On the platform side, we’re building the Niobium Fog™, a cloud environment that allows customers and partners to run encrypted workloads and applications using that same custom silicon.
Because faster hardware is useful.
Making it accessible is what actually changes adoption.
You don’t replace TLS with FHE.
You use FHE where the cost of exposure is higher than the cost of computation.
Healthcare
Finance
Defense
AI
Places where “just trust us” gets expensive fast.
The Short Version
TLS protects data in motion.
AES protects data at rest.
FHE protects data in use.
And once you see that third category…
you start noticing how often it’s missing.
What’s Next
In the next post, we’ll look at something that sounds complete, but isn’t:
Why “encrypted at rest and in transit” became the industry standard…
and why it quietly leaves out the most important part.
Because sometimes the biggest security gap
is the one everyone agreed not to look at too closely.
To learn more about FHE, hardware acceleration, and Niobium’s encrypted cloud platform, The Fog™, contact us or sign up to join our beta!
