The Quantum Security and Post-Quantum Cryptography Company Landscape: Who Is Building the Chips and Software That Will Protect Us From Q-Day

[NatureBoyDylan81]

The quantum computing IPO wave covered elsewhere on this forum is only half the story. Running parallel to it is a different race entirely: the companies building the cryptographic defences that will need to be in place before a cryptographically relevant quantum computer exists. Post-quantum cryptography, or PQC, is the field of mathematics and engineering that produces encryption algorithms strong enough to resist a quantum computer's attack. NIST finalised its first three PQC standards in August 2024 and selected a fourth in March 2025. The US government's June 22 executive orders now mandate federal agencies begin migrating immediately, with defence contractors on the strictest timeline of 2027. Every company below is either already in a race to embed these algorithms into silicon, or selling the software platforms that help enterprises migrate. Some are already public. Some are heading there fast.

SEALSQ Corp (Nasdaq: LAES) and parent WISeKey International (Nasdaq: WKEY / SIX: WIHN) made the most significant structural move in the PQC space this week. On June 25 they announced the formation of Quantisimo Corp, a special purpose vehicle that has signed a non-binding Letter of Intent with GigCapital8 Corp (Nasdaq: GIW) to explore a business combination that would create a consolidated Nasdaq-listed quantum technology platform. The initial pre-money enterprise value is approximately $575 million. The parties intend to grow this to $2 billion through the acquisition of up to five additional quantum companies. The transaction is expected to close in Q1 2027, subject to definitive agreements, regulatory and shareholder approvals, and customary conditions. SEALSQ develops quantum-resistant semiconductors, PKI infrastructure and post-quantum technologies. Its QS7001 Post-Quantum Secure Element was aligned with the new French national cybersecurity agency ANSSI post-quantum mandate in June 2026, and SEALSQ presented at IQT Nordics 2026 calling for accelerated PQC migration across Europe. WISeKey CEO Carlos Creus Moreira described the Quantisimo vehicle as designed to provide investors direct exposure to the emerging quantum economy. (Sources: GlobeNewswire June 25 press release announcing the LOI and $575 million enterprise value; Quantum Computing Report June 25 covering the Quantisimo-GigCapital8 combination structure; SEC Form 8-K filed by GigCapital8 confirming the LOI and transaction terms on June 25.)

STMicroelectronics (NYSE: STM) launched what it describes as the world's first monolithic mobile chip with a dedicated PQC hardware accelerator on June 24. The ST54M integrates an NFC controller, a secure element, full eSIM functionality, and a hardware accelerator supporting the NIST-standardised ML-KEM and ML-DSA algorithms, all on a single die. This matters because previous approaches handled PQC in software, which is slower, more power-hungry and less secure than silicon-level implementation. The ST54M targets smartphones, wearables and personal electronics for use cases including contactless payments, digital identity, transit ticketing, access control, driving licences and digital car keys. Sampling began immediately. Volume production and Common Criteria EUCC and EMVCo certification are targeted for July 2026. The chip is designed to comply with quantum-ready security requirements expected to be mandated by 2030. VP David Richetto described it as giving device makers a secure path to start preparing next-generation mobile experiences. (Sources: STMicroelectronics official press release via GlobeNewswire June 24 announcing the ST54M launch; The Quantum Insider June 24 covering the ML-KEM and ML-DSA integration and July 2026 production target; STMicroelectronics official newsroom page at newsroom.st.com confirming sampling availability and certification timeline.)

EnSilica plc (AIM: ENSI) is the British chip designer that most people outside the semiconductor and quantum sectors have not heard of, and which is quietly becoming one of the more important UK companies in the PQC hardware space. EnSilica is headquartered in Abingdon, Oxfordshire, listed on London's AIM market, employs 179 people and operates in the UK, India, Brazil and Germany. It designs mixed-signal ASICs for customers in automotive, industrial, satellite communications and defence. What makes it relevant here is twofold: its eSi-Crypto PQC IP library, and the £5 million Contract for Innovation awarded by the UK Government's Department for Science, Innovation and Technology in November 2025. The eSi-Crypto library adds hardware-accelerated PQC cores implementing NIST-standardised algorithms to licensable IP that customers embed in their own chips. The first licence was granted to a major semiconductor company for use in a 5nm networking chip, announced in January 2024. The DSIT contract, announced November 14 2025, funds EnSilica to develop a CHERI-architecture secure processor for critical national infrastructure applications, combining the Capability Hardware Enhanced RISC Instructions memory safety architecture with EnSilica's PQC accelerator IP. Phase 1 at £1.5 million covers specification and prototype, targeting completion in March 2026. Phase 2 at £3.5 million covers full design verification, silicon manufacturing and productisation by March 2028. EnSilica has shipped over ten million ISO 26262 ASIL-D qualified automotive chips and reported H1 FY2026 revenues of £12.7 million, up 37 percent year-on-year, with guidance for full-year revenues of £28 to £30 million. (Sources: EnSilica official press release November 14 2025 on the DSIT £5 million contract for the CHERI PQC processor; EnSilica official website product page confirming eSi-Crypto PQC IP library and first 5nm networking chip licence; Quantum Zeitgeist November 2025 article covering the £5 million award, CHERI architecture, and defence, automotive and aerospace sector targeting.)

BTQ Technologies (Nasdaq: BTQ) listed on Nasdaq on September 26 2025, making it one of the first post-quantum cryptography pure-plays to reach a US major exchange. The Vancouver-based company builds hardware-accelerated PQC solutions for critical infrastructure and blockchain. It acquired Radical Semiconductor's CASH cryptographic accelerator architecture, launched Bitcoin Quantum Core 0.2 in October 2025 as the first quantum-resistant Bitcoin implementation replacing ECDSA with NIST-standardised ML-DSA, and signed a $15 million strategic partnership with Korean semiconductor firm ICTK to co-develop a Quantum Compute in Memory security chip. It also acquired QPerfect, the neutral-atom quantum simulation company. On June 27 2026 it appointed Brandt Pasco as US Strategic Advisor for Post-Quantum Cryptography and Security, explicitly to align BTQ's portfolio with federal deployment priorities following the Trump executive orders. BTQ's market capitalisation is approximately $1.3 billion against very modest revenue, reflecting investor pricing of the regulatory mandate pipeline. (Sources: Quantum Computing Report June 27 covering the Brandt Pasco strategic advisor appointment; entangledfuture.com PQC company guide confirming the BTQ Nasdaq listing date, CASH acquisition and ICTK $15 million partnership; The Quantum Insider post-quantum company landscape confirming the Bitcoin Quantum Core 0.2 launch and QPerfect acquisition.)

PQShield is the Oxford University spinout that is one of the only PQC companies to have taped out and demonstrated a working post-quantum cryptography chip in silicon, alongside its software and cloud-based implementations. The company has 91 employees, holds 30 patent families across lattice cryptography and side-channel resistance, and counts AMD, Microchip Technology, Collins Aerospace and Lattice Semiconductor as customers. Backers include Addition, Chevron Technology Ventures, Legal and General, and Oxford Science Enterprises. PQShield achieved FedRAMP Ready status in December 2025, unlocking US federal sales channels. Recent wins include Dow Chemical, Mayo Clinic and a deployment across 60 Bahrain government ministries. It is not yet public but pre-IPO shares are available through EquityZen for accredited investors. No confirmed IPO date exists. (Sources: quantumzeitgeist.com post-quantum cryptography company guide confirming 91 employees, 30 patent families, and AMD and Microchip customer relationships; equityzen.com PQShield profile confirming pre-IPO share availability and investor backing; entangledfuture.com PQC guide confirming FedRAMP Ready status December 2025 and Bahrain ministry deployment.)

Qwerx Inc is a Vienna, Virginia company founded in 2020 that takes a fundamentally different approach from the PQC field. Rather than implementing the new NIST lattice-based mathematical algorithms, Qwerx replaces static credentials entirely with ephemeral rotating symmetric keys that it describes as quantum-proof. The core product, QESP, the Qwerx Enterprise Secure Perimeter, is a cloud-native SaaS that prevents unauthorised devices from accessing protected networks by enrolling every machine and replacing its static authentication credentials with chaotically generated ephemeral keys that rotate continuously. Real-time attack warnings push to administrators including metadata and telemetry. The technology targets zero-trust mandates across critical infrastructure, terrestrial and space-based assets, edge devices in austere environments and unmanned systems. CB Insights includes Qwerx in its quantum technology, defence technology and critical infrastructure expert collections, and notes the company's most recent funding round is Debt. The DashVixel Holdings relationship positions Qwerx within a broader AI and quantum methodology portfolio. Qwerx is pre-IPO, private, and has not confirmed a public markets timeline. (Sources: CB Insights Qwerx company profile confirming the Vienna Virginia location, founding year 2020, QESP product description and expert collection categorisation; Qwerx company website qwerx.co confirming the ephemeral symmetric key approach and zero-trust positioning; DashVixel Holdings press material confirming the corporate relationship and Baystone Group contact information.)

SandboxAQ, the Alphabet spinout from 2022, is the largest private company in this space by valuation, having raised over $1.4 billion at a $5.3 billion valuation. It focuses on the intersection of AI and post-quantum cryptography migration, providing enterprise services to help large organisations inventory their cryptographic infrastructure, identify vulnerabilities, and execute migration to NIST PQC algorithms. Its backing includes Eric Schmidt and Marc Benioff. An IPO in late 2026 or 2027 is widely expected but no formal filing exists as of the research date. (Sources: quantumzeitgeist.com confirming $1.4 billion raised at $5.3 billion valuation and expected late-2026 or 2027 IPO; entangledfuture.com IPO guide confirming no formal filing as of March 2026; Quantum Computing Report June 27 covering SandboxAQ's backing of the Trump quantum executive orders and PQC migration mandate.)

WISeKey and SEALSQ Establish Quantisimo Corp. and Execute Nasdaq SPAC Listing Intent with GigCapital8 - Quantum Computing Reportquantumcomputingreport.com

[PlanetOftheApes]

Interesting that quantum gets framed as a compute race when the security side may end up touching more people sooner. Nobody outside tech circles cares how many qubits exist until their bank, VPN, or government portal starts changing protocols. The boring migration work might end up being the bigger business.

Also feels like there are going to be a lot of companies selling shovels during the gold rush phase.

[DecentBloke]

The chip angle gets less attention than it should. Everyone talks algorithms but somebody still has to accelerate key exchange, signatures, and all the ugly transition layers in hardware.

Feels a bit like the early TPM era where security hardware existed for years before normal users noticed.

[Louise82]

One thing that keeps coming to mind is how much of this market depends on timing. If practical cryptographically relevant quantum arrives late, some of these companies burn cash for a decade waiting for demand.

If it arrives suddenly, the companies with migration tooling rather than pure research might clean up.