When Encryption Isn’t Enough: Why Human Behavior Still Decides Security

Earlier this week, CISA issued a warning that state-backed threat actors and cyber-mercenaries are using commercial spyware to compromise accounts on ultra-secure messaging apps like Signal and WhatsApp. They’re not breaking Signal’s encryption. They’re not cracking some secret weakness in WhatsApp. They’re going around the encryption entirely.

They’re attacking the human and the device.

This point may seem obvious, but it’s one we collectively forget far too often:
security isn’t just about strong tools — it’s about strong habits.
Every layer matters. And most breaches don’t happen because the cryptography failed, but because the end-user did.

Let’s talk about why this matters — especially for communities and teams who rely on secure communications.

The Real World Problem: Humans Are the Weakest Link

CISA’s bulletin explains how attackers compromise phones using:

• malicious “linked device” QR codes,

• poisoned images or files that exploit WhatsApp’s previewing behavior,

• fake “updates” that look real but install spyware,

• spoofed versions of legitimate messaging apps,

• and old-fashioned social engineering that tricks people into giving a foothold away.

At no point does the attacker need to decrypt anything. They simply compromise the environment before the encryption ever has a chance to protect you.

This is the part too many people forget:

When your device is compromised, encryption becomes meaningless.

A keylogger doesn’t care that your messages are “end-to-end encrypted.” Screen-scrapers don’t care that the protocol is mathematically sound. Malware doesn’t care how many bits your key contains.

The attack surface isn’t the encryption.
It’s you.

Layered Security Matters (And Layers Are Only as Strong as Their Weakest Link)

This is where we have to embrace a painful truth:

Every secure system — apps, radios, mesh networks, encryption protocols — is only as secure as the least disciplined human using it.

When we talk about “layers of security,” we often think of:

• encryption algorithms

• authentication

• access control

• network separation

• physical separation

• firmware integrity

• device hardening

But there’s a final layer that too many people ignore: the operational layer.

That’s the layer where humans either do the smart thing (hopefully!) or the catastrophic thing (more often than we care to admit).

Where Shielded Signals Fits Into This Conversation

For the record:
Shielded Signals has absolutely nothing to do with CISA’s announcement. Our systems weren’t involved. Our customers weren’t targeted. Our tools weren’t mentioned in any way.

But the lesson applies to everyone in the security and privacy space! it reinforces the principles that drive how we design our own communications ecosystem.

Here’s how Shielded Signals approaches this very problem:

1. Off-grid means off-grid.

OUR radios and our mesh appliance don’t rely on the Internet, the cloud, Big Tech servers, or mobile carriers.
If a tool can’t be remotely attacked through a global network, that eliminates an enormous class of threats.

2. Encryption keys are sacrosanct.

We treat encryption keys like crown jewels:

• never accessible to customers

• never readable from radios

• never present in cleartext anywhere

• protected against extraction even through firmware overwrites

If someone’s device is compromised, the attacker still cannot steal Shielded Signals keys.

3. Firmware integrity is non-negotiable.

We design, compile, and load our firmware in-house.
No third-party stores it.
No public GitHub repository reveals key handling routines.
No downloadable codeplug contains anything sensitive.

4. Physical control matters.

Because our systems are purpose-built radios and appliances — not general-purpose smartphones — the attack surface is dramatically smaller.
There’s no App Store, no browser, no random QR codes, and no background processes to exploit.

5. Discipline beats software.

This one applies to everyone, including us:

• beware social engineering;

• avoid sharing devices;

• maintain physical control;

• remain aware of your operational environment.

The best system in the world can’t save a careless user.

The Hard Reality: Security Is a Partnership

We can build strong tools.
We can engineer hardened firmware.
We can design off-grid, closed-loop communications that are practically unreachable for online gangs and cyber-mercenaries.

But we can’t prevent someone from doing something careless with their device.

CISA’s warning isn’t about the failure of encryption.
It’s a reminder that humans are part of the security perimeter — and must behave like it.

Whether it’s Signal, WhatsApp, satellite messengers, or the Shielded Signals mesh appliance, the principle is the same:

No system is secure if the user ignores security.

Tools matter.
Design matters.
But discipline matters most.

Final Thought

As technology advances, the threats become more sophisticated. the lessons need to do the same.
The recent spyware campaign targeting encrypted apps should be a wake-up call: the adversary isn’t always attacking your encryption. Sometimes they’re attacking you.

At Shielded Signals, we’ll continue building systems that minimize those risks. systems that stay off-grid, protect keys at every step, and narrow the attack surface to the smallest possible footprint.

But security will always be a shared responsibility.

Stay disciplined. Stay aware. Stay secure.