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ICSL – Secure Communications
ICSL Consulting ↗
Why ICSL?

Exclusively COMSEC. For 30+ years.
No conflicts of interest.

ICSL focuses exclusively on communications security (COMSEC) — we are not a general IT systems provider or a distributor- or manufacturer-driven sales operation. We dedicate ourselves entirely to our customers' communications security.

Four Reasons to Choose ICSL

What sets us apart from every other provider — and why it matters for security.

Exclusively COMSEC. For 30+ years.

30+ years focused on communications security (secure communications)

  • Founded in 1995 as an internet and telecommunications company
  • 1997: public network operator launched as a spin-off
  • 2001: secure communications solution for our first government customer
  • No general IT business — 100% COMSEC
  • In-depth product knowledge from decades of use
  • Comprehensive telecommunications expertise from the ground up
  • Experience from real government deployments worldwide
  • Austrian, neutral, independent
  • Multilingual operations & support — German, English, Russian, Ukrainian and more
  • Family-run, privately held — continuity, personal responsibility & loyalty
Our history →

We examine the details

Independent technical evaluation rather than manufacturer marketing

  • Thorough technical evaluation of every solution before recommendation
  • No commission pressure — the customer pays our bill
  • Honest assessment of strengths and limitations
  • Independent testing and penetration testing where possible
  • No manufacturer can “buy” our recommendation
Our methodology →

Discretion & Principles

No customer names in marketing — zero knowledge as a principle

  • No customer names in our marketing
  • Customers are mentioned only if they have made the relationship public themselves
  • Confidentiality as a core business principle since our founding
  • Neutral: no political, national or commercial ties
  • NDAs as standard for all engagements
  • Vienna as a neutral location — outside Five Eyes and EU intelligence services
Our principles →

Approvals & Clearances

FCL, PCLs, NATO approval, ISO 27001 data centres

  • Facility Security Clearance (FCL) for classified environments up to Secret level (currently valid until 03-2028
  • Personnel Security Clearances (PCLs) up to Secret level until 03-2028
  • NATO-approved solutions form the foundation of the portfolio
  • ISO 27001-certified data centre partners
  • Ongoing reviews and recertification
All approvals →
Testing & Evaluation

We look closely — even where others look away

Security depends on detail. One incorrect parameter, an overlooked log entry, an untested fallback configuration — and a system that appears secure is not.

Ongoing Solution Testing

We test solutions for customers and on our own initiative. This gives us first-hand knowledge of their strengths and weaknesses, including vulnerabilities and missing features.

Regular Configuration Audits

What is secure today may have a vulnerability tomorrow. ICSL reviews proactively, not only when problems arise.

Honesty Supports Security

If a solution has a weakness, we inform our customers — even if the manufacturer is a long-standing partner.

Understand Your Requirements

Many of your real needs emerge during use. With ICSL, you do not need a full rollout to discover them. We also provide pilots for 1 year.

No One-Size-Fits-All Approach

Every customer has different requirements — and we can usually address them specifically.

Experience with Problems, Too

Years of experience give ICSL the expertise to know where to look when assessing solutions or diagnosing faults.

Long-Term Responsibility

ICSL takes responsibility for systems over many years — beyond delivery.

See for Yourself

Test our solutions first-hand on ICSL infrastructure in an ISO-27001-certified data centre in Vienna — experience quality, simplicity and reliability in real use.

We Measure Rather Than Assume

For example, a customer commissioned us to test eleven commercially available communications solutions, including approved government apps and well-known business messengers, on iOS and Android. We tested under stress: at 30–50 % packet loss, with 20 kbit/s remaining bandwidth, during call waiting, switching and holding, when changing networks mid-call, and with CarPlay and Android Auto. The results were sobering: few solutions remain reliably usable under real-world conditions. Approval alone does not guarantee practical usability — nor do widespread adoption and heavy promotion.

We Analyse Rather Than Guess

When operational problems arise, we do not guess: we analyse the logs of all connections, not just reported cases — revealing patterns that individual tests cannot show. In one installation, for example, quality problems occurred precisely during office hours, with identical packet loss for both participants regardless of their network: a clear indication of the underlying infrastructure rather than the app. We also demonstrate test results live to customers on request.

ICSL — since 1995

30+ Years — Telecommunications and Communications Security

ICSL does nothing else. No IT services, no cloud consulting, no hardware bundles. Exclusively telecommunications and communications security — since 1995.

No Chasing Trends

Zero trust, quantum, AI security: ICSL implements technology when it is mature, not merely marketable.

The Difference from Your Systems Integrator's IT Department

Many organisations buy communications security as an add-on to a larger IT contract. That is understandable — and often dangerous.

ICSL was founded before encryption became commonplace in messaging apps. Many of our customers today did not yet know then that they would one day need us.

A Brief History of Specialisation

30 years — telecommunications and secure communications: the same focus, ever deeper expertise.

95

Founded in 1995

ICSL is established as a specialist internet and telecommunications company.

97

Alternative Public Network Operator

An ICSL spin-off — the first alternative public network operator with interconnection to the incumbent goes live.

01

2001: Specialisation in Secure Communications — First Customers

Government agencies, ministries and armed forces become regular customers. ICSL establishes itself as a trusted partner for classified communications for government agencies, businesses and VIPs.

10

Users in over 20 Countries from 2010

NATO-approved solutions bring new engagements.

20

Serving an Entire Country's Senior Administration

ICSL provides highly secure communications in a custom configuration to an entire country's senior administration, federal authorities and ministries. For the first time, ministers could exchange classified information across departments with a high level of security. Voice, video, chat, files, conferences and more.

25

Post-Quantum and New Threat Landscapes from 2025

ICSL can deliver the first NATO-approved messenger solution with fully and comprehensively integrated post-quantum cryptography.

26

Today: 30+ Years, 1 Focus

ICSL remains exclusively focused on communications security. No general IT, no assortment of unrelated services, no one-way relationship, no conflicts of interest — just the customer.

Management & Senior Partners

Personally accountable. For decades.

LS

Ludwig Seidl

CEO / Founder

PCL – Secret
DK

Deniz Kyazimov

CTO / Senior Partner

PCL – Secret
YS

Yulia Seidl

CAO / Senior Partner

Behind them is an established operations, support and technical team, alongside liaison and partner managers — supplemented when needed by associated companies and experts from TU Wien. Privately run, financially strong, with no liabilities to suppliers or banks: independent, discreet and neutral.

Let's speak personally!

We would be pleased to offer you a confidential briefing without obligation.