Silentel 9: Post-Quantum Cryptography, Live in Production

Silentel has always used AES for symmetric encryption, RSA and later elliptic curve cryptography for asymmetric protection, a combination that has exceeded the requirements of the US Top Secret communication standard for years. With Silentel 9, that foundation gets a second, independent layer sitting alongside it: post-quantum cryptography, deployed now, well ahead of when it becomes a regulatory requirement anywhere.

An additional layer, not a replacement

It's worth being precise about what this actually changes, because it's easy to assume a new cryptography layer means the old one is being retired. It isn't. Post-quantum cryptography in Silentel 9 sits on top of ECC as a fully capable second layer, not a substitute for it. In practice, encryption keys are first secured with ECC, then additionally encrypted with post-quantum algorithms. The two methods work as genuinely independent encryption principles. If one of them were ever broken in the future, whether that's a theoretical break in ECC or a future weakness found in a post-quantum algorithm, communication stays fully protected by the other.

That layered design matters more than a straight swap would. Post-quantum algorithms are still relatively young compared to the decades of scrutiny ECC has been through. Treating PQC as an addition rather than a replacement means Silentel isn't betting communications security on a newer, less battle-tested set of algorithms alone, and isn't leaving classical protection behind either.

Running two independent, fully capable encryption layers at once is not a small technical lift when one of them is post-quantum cryptography. PQC algorithms carry meaningfully larger key and signature sizes and heavier computational overhead than ECC, which is exactly the kind of thing that tends to show up as lag, delay, or dropped reliability once it's deployed for real. Silentel 9 runs both layers together without any drop in call quality or messaging performance, a result a number of other PQC rollouts elsewhere in the industry have struggled to match without running into exactly those tradeoffs.

Why now, when the threat isn't here yet

Quantum computers capable of breaking today's encryption don't exist yet. That's true, and it's also not really the point. Attackers are already using what's known as a store now, decrypt later strategy: capturing encrypted communications today with no ability to read them yet, and simply waiting for the computing power to catch up. Under that strategy, data can become compromised retroactively, not at the moment it was sent, but years later once the capability to break it finally exists.

For any communication that needs to stay confidential for years, not just for the length of the conversation itself, that risk is already live, regardless of when a capable quantum computer actually arrives. Deploying post-quantum protection now, rather than waiting for a mandate, is what actually closes that window.

It's also worth being honest about where these standards actually stand today. No quantum computer large enough to meaningfully attack algorithms like ML-KEM or ML-DSA exists yet, which means the standards themselves haven't been tested against the real thing, only against classical cryptanalysis and years of academic review. That's not a reason to wait. It's a reason to treat post-quantum cryptography as a prudent additional layer rather than a proven replacement, which is exactly the approach Silentel 9 takes by keeping ECC fully in place alongside it.

A deadline that's already been set

This isn't a purely theoretical concern being addressed early out of caution. The European Union has set 2030 as the deadline by which post-quantum protection should be fully deployed in critical systems, and international guidance broadly agrees that the transition should begin without unnecessary delay. Silentel 9 puts that protection into production years ahead of that line, rather than treating it as a future compliance exercise.

Built to hold up on a bad connection

Post-quantum cryptography is the headline, but Silentel 9 also puts real work into something just as important for a secure communications platform: what happens when the network itself isn't cooperating. Call quality has been significantly improved with better resilience to high packet loss and latency, so conversations stay usable in conditions that would previously have made them choppy or unreliable. The release also adds support for comfort noise during calls, filling the silence during pauses so a call doesn't sound like it's dropped when it hasn't, and improves how the app re-establishes a call after a connection is interrupted, aiming for a faster, more reliable recovery rather than leaving users to redial and hope.

None of this matters much on a strong office connection. It matters a great deal in the field, on a moving vehicle, or anywhere else the network can't be counted on, which is exactly where a lot of Silentel's government and defence use actually happens.

Small conveniences that add up

Message downloading is faster in this release, so the app catches up more quickly after being offline or reconnecting. Sending a file now allows a short description or note alongside it, so the recipient has context without needing a separate message to explain what they're looking at. And files can now be sent directly during an active call, rather than needing to end the call first or juggle two separate actions to share something mid-conversation.

What this means for anyone running Silentel

• Layered, not swapped: communications are now protected by both ECC and post-quantum cryptography independently, so a future weakness in either one doesn't leave data exposed.
• Protection against a threat that's already acting: store now, decrypt later attacks are a present-day risk against anything encrypted with classical methods alone, not a future one.
• Ahead of the deadline, not racing toward it: with the EU's 2030 target already set for critical systems, deploying this now means it's a settled part of the platform rather than a last minute migration later.
• More reliable in the conditions that actually matter: better handling of packet loss, latency, and dropped connections means the platform holds up better exactly where communication tends to be hardest, in the field rather than at a desk.

Older versions of Silentel will only remain supported for a limited time following this release, so updating isn't just a matter of picking up a new feature, it's what keeps communications inside the protection this release was built to provide.