StarTech CK4-D104C 4-Port Secure DVI KVM Switch NIAP 4.0

Overview

The StarTech CK4-D104C is a 4-port secure KVM switch purpose-built for environments where data isolation between hosts is a non-negotiable requirement. Carrying NIAP Protection Profile for Peripheral Sharing Devices version 4.0 certification, this unit meets the security baseline required for classified government networks, defense contractor workstations, and high-security enterprise deployments where conventional KVMs present an unacceptable cross-contamination risk.

The CK4-D104C supports DVI video output to a single console monitor, with up to four isolated host connections. Each port is electronically isolated — there is no software-based switching here. The all-metal chassis (12.6 in × 6.7 in × 1.8 in, 4.2 lb) is built to sit on a desk or in a secure workspace, not a rack. If you need to control multiple classified and unclassified hosts from a single keyboard, mouse, and display without risking data leakage between them, this is the correct product class to be evaluating.

Key Features

• NIAP Protection Profile 4.0 Certification: This is the current and most stringent NIAP PSD standard. It mandates hardware-enforced isolation, anti-tamper protections, and strict data path controls — meaning your security auditors and accreditation teams can point to a verifiable standard, not a vendor claim. Without NIAP 4.0, a KVM switch cannot be used on many classified or DoD-adjacent networks.
• 4 Isolated Host Ports: Supports up to four hosts simultaneously connected, switchable to a single console. Each host connection uses dedicated hardware paths — 8× DisplayPort female connectors, 8× HDMI connectors, 4× 3.5mm stereo female audio jacks, and 8× USB 2.0 Type-B ports on the host side — so no single data bus is shared between sources in a way that could allow covert signaling.
• DVI Console Video Output: The console-side video interface is DVI, which keeps compatibility straightforward for existing secure workspace monitor setups. The console also exposes 2× DisplayPort and 2× HDMI interfaces, giving you flexibility in how you connect your single display without requiring an adapter chain that could introduce a security gap.
• USB 2.0 Keyboard and Mouse Support: Three USB 2.0 Type-A ports on the console side handle your keyboard, mouse, and an optional third peripheral. USB HID emulation ensures each host sees a consistent device — no re-pairing delays when you switch ports, which matters when you are moving between time-sensitive workstations.
• Integrated Audio Switching: A single 3.5mm stereo jack on the console side routes audio from the active host. Four corresponding 3.5mm jacks on the host side mean audio follows the KVM switch — you do not need a separate audio matrix or manual cable swaps when moving between hosts.
• Maximum Cable Length 19.7 ft (6 m): Host machines can be located up to 6 meters from the switch, which gives you flexibility in placing hosts inside secure enclosures or behind barriers while the operator console stays accessible. Exceeding this distance risks signal degradation on the DVI/USB runs.
• All-Metal Chassis: The metal construction is not just about durability — it contributes to EMI shielding, which matters in environments sensitive to electromagnetic eavesdropping or signal injection. Plastic-bodied KVM switches are generally not acceptable in TEMPEST-adjacent deployments.
• Operating Temperature 0°C to 40°C: Rated for standard indoor office and data center ambient conditions. Storage down to -20°C makes shipping and warehousing in cold climates straightforward without special handling requirements.

Integration and Compatibility

The CK4-D104C (often searched as CK4 D104C) is designed for deployment in single-user, multi-classification workstation environments — think intelligence analyst desks, secure operations centers, or contractor facilities handling CUI alongside classified material. The NIAP 4.0 certification is the key integration credential: check your facility's approved products list (APL) and accreditation requirements before procurement to confirm this version satisfies your AO's specific requirements.

On the host side, the dual DisplayPort and HDMI connectors per port give you flexibility with modern workstation GPU outputs. On the console side, the 2× DisplayPort and 2× HDMI outputs alongside the DVI interface mean you can match whatever monitor input is available in your secure workspace. Audio integration is built in — no need for a secondary KVM or audio switcher to handle headset or speaker connections.

For deployments requiring compliance with secure KVM switches standards, the NIAP 4.0 rating is a concrete checkpoint. Pair this unit with a verified NIAP-evaluated monitor and NIAP-compliant keyboard and mouse for a fully accreditable console stack. Review the full StarTech product line for companion peripherals and cables validated for secure environments.

If your facility operates a managed network infrastructure with strict port-level access controls, the CK4-D104C fits cleanly into that architecture — it adds no network interface and introduces no IP-accessible attack surface, which is precisely the point for air-gapped deployments.

Frequently Asked Questions

Q: What NIAP certification level does the CK4-D104C hold?

A: The CK4-D104C is certified to NIAP Protection Profile for Peripheral Sharing Devices version 4.0, the current and most stringent published standard for secure KVM switches. Verify against your facility's Approved Products List before procurement.

Q: How many hosts can be connected to the CK4-D104C simultaneously?

A: Four hosts can be connected simultaneously. The switch routes one host at a time to the single console (keyboard, mouse, and display), with hardware-enforced isolation between all host ports.

Q: What video interfaces does the CK4-D104C support on the host side?

A: Each of the four host ports provides two DisplayPort female and two HDMI connectors, for a total of 8 DisplayPort and 8 HDMI host-side connections. The console output is DVI, with 2× DisplayPort and 2× HDMI also available on the console side.

Q: What is the maximum cable run between a host and the CK4-D104C?

A: StarTech specifies a maximum cable length of 19.7 ft (6 m) between host and switch. Longer runs risk signal degradation on DVI and USB 2.0 connections.

Q: Does the CK4-D104C support audio switching?

A: Yes. The unit includes four 3.5mm stereo female jacks on the host side and one 3.5mm stereo female jack on the console side, so audio follows the active KVM channel automatically.

Q: What is the warranty on the CK4-D104C?

A: StarTech provides a 3-year manufacturer warranty on the CK4-D104C.

Karl Wilson

The CK4-D104C is one of the few KVM switches I would recommend without hesitation for a multi-classification analyst workstation — specifically because the NIAP 4.0 certification means the isolation architecture has been independently evaluated, not just claimed by the vendor. That distinction matters when your accreditation officer is signing off on a deployment that touches classified networks.

Technical Highlights:

• NIAP 4.0 Hardware Isolation: Version 4.0 of the NIAP PSD profile is the current standard — it closes attack vectors that were present in earlier PSD versions, including optical data diode requirements and stricter anti-tamper provisions. If a facility specifies NIAP PSD 4.0 specifically, earlier-version switches do not qualify.
• 8× USB 2.0 Type-B Host Ports: Two USB Type-B connections per host port means you can run keyboard and mouse from each host without sharing a USB bus, which is critical for maintaining the hardware isolation the NIAP certification requires. Don't assume one USB-B per host is sufficient for your peripheral load.
• 6m Maximum Cable Length: At 19.7 feet, you have enough run to place host workstations inside a separate locked enclosure or behind a physical barrier while keeping the operator console accessible — a common physical security requirement in SCIFs and secure workspaces.

Deployment Considerations:

• Confirm your facility's Approved Products List includes the CK4-D104C under NIAP PSD 4.0 before procurement — NIAP evaluations are version-specific and your AO may require the exact evaluated configuration.
• The maximum 6m cable run is a hard constraint — if your hosts are more than 19.7 feet from the console position, you will need to reconfigure the physical layout rather than extend the cable, as USB 2.0 signal integrity degrades predictably beyond this distance.

This unit fits best in a two- to four-classification analyst desk where the operator needs to move between a classified and unclassified host several times per hour without the friction of physical cable swaps — and where the accreditation package requires a listed, evaluated device rather than a commercial KVM with a vendor security claim.