A large enough quantum computer would break the public-key cryptography that protects almost everything online today, including RSA and elliptic curve key exchange and signatures. Nobody can say exactly when that machine will exist, but the risk is already live. Attackers can collect encrypted traffic and data now and decrypt it later, a pattern known as harvest now, decrypt later. Anything that must stay confidential for ten years or more, such as health records, financial data, intellectual property or state secrets, is exposed today.
The standards are now in place. On August 13, 2024, NIST published its first three finalized post-quantum standards: FIPS 203 (ML-KEM, based on CRYSTALS-Kyber) for key encapsulation, FIPS 204 (ML-DSA, based on CRYSTALS-Dilithium) for digital signatures, and FIPS 205 (SLH-DSA, based on SPHINCS+) as a hash-based backup signature scheme. A further signature standard based on FALCON, FN-DSA, is planned as FIPS 206. The hard part is not choosing an algorithm. It is finding every place your organization uses cryptography, deciding what to fix first and changing it without breaking production systems.
That is the work post-quantum cryptography consulting firms do. The ten below were checked against their own PQC service pages and ranked on the depth of their discovery, migration and crypto-agility services. Quantum is not the only cryptographic risk, and AI-assisted attacks are already testing weak key management, as our guide to AI-powered threats to cybersecurity explains.
Post-Quantum Cryptography Consulting Firms At A Glance
Company
Headquarters
Best For
Core Services
IBM
Armonk, USA
Large enterprises that want consulting backed by discovery and remediation tools
Best Post-Quantum Cryptography Consulting Firms For 2027
1. IBM — Quantum Safe Transformation Services Plus Explorer, Manager And Proxy Tools
IBM runs quantum safe transformation services as a three-phase engagement: understand the cryptographic risk, assets and priorities; prepare for migration with a quantum-safe roadmap and crypto-agile strategy; then implement and scale quantum-safe cryptography across the organization and its supply chain.
The consulting is backed by IBM’s own software. Quantum Safe Explorer scans application source code to find cryptographic assets and quantum-vulnerable algorithms and maps their dependencies. Quantum Safe Cryptography Manager helps plan and track migration steps, and Quantum Safe Proxy protects applications and network traffic with hybrid classical and post-quantum cryptography without code changes. For enterprises running IBM Z, IBM Cloud or Red Hat platforms, the same vendor can also address quantum-safe capabilities in that infrastructure. IBM suits large organizations that want one partner for strategy, tooling and delivery.
2. Accenture — Cryptographic Center Of Excellence With Four-Phase PQC Migration
Accenture’s post-quantum approach starts with a Cryptographic Center of Excellence that brings legal, security, IT and product teams together to map quantum threat impact and build roadmaps with timelines and budgets. Inventory comes next: Accenture Discovery Plus analyzes systems with source code, while a forensic review of architecture diagrams and network flows covers systems without code access.
From there, Accenture remediates first and third-party code where possible, replaces outdated components where necessary, and deploys a policy-driven orchestration engine for cryptographic agility that automates client updates, endpoint policy changes and certificate renewals. Work then iterates across the remaining inventory, including public and private certificates and authentication systems, with ongoing health monitoring and governance reviews. Accenture has documented this approach with AWS for hybrid and multi-cloud workloads, which makes it a strong fit for large enterprises with a heavy cloud footprint and many teams to coordinate.
3. Deloitte — Cryptography Inventory, Roadmap And Governance For Regulated Firms
Deloitte’s quantum cyber readiness services cover three areas. Cryptography Inventory, Analysis and Roadmap maps where cryptography is used, how it supports trust in core operations and where it is vulnerable to quantum or conventional threats, then delivers a roadmap. Post-Quantum Cryptography Implementation and Transition plans and executes the migration of systems to quantum-secure technologies.
Deloitte’s third area, Governance and Compliance, is what sets it apart for regulated buyers. It provides industry-specific knowledge to build the structures and culture needed to keep pace with changing standards, regulations and technology. Banks, insurers, healthcare systems and public sector bodies often need PQC planning to fit into existing risk, audit and regulatory reporting, and a firm with a large risk advisory practice can connect those pieces. Deloitte says it has helped large organizations become more crypto-agile, which matters because PQC standards will keep evolving after the first migration.
4. Capgemini — CBOM Discovery Feeding A PQC Migration Factory
Capgemini’s post-quantum readiness offering covers strategy and assessment, governance, pilots and implementation. Assessment includes risk and maturity reviews aligned to NIST PQC standards, prioritized across applications, infrastructure, PKI, APIs, cloud services, OT, IoT and third-party ecosystems. Cryptographic discovery produces a Cryptographic Bill of Materials (CBOM) as the foundation for planning.
Capgemini stands out for delivery at scale. Pilots test hybrid PQC and crypto-agility with PKI modernization and KMS and HSM integration, and produce reference architectures, migration playbooks and reusable patterns. Those then feed a migration factory model that covers TLS, signing, identity and certificate modernization and remediation across applications, cloud, OT, IoT and partner ecosystems, with testing, assurance and operational monitoring. Governance work sets up executive reporting and cryptographic, key management and certificate lifecycle policy. It is a good match for global companies with thousands of applications and industrial systems to migrate.
5. CGI — NCSC-Assured PQC Discovery With A Quantum Risk Heatmap
CGI’s PQC Essentials offering is a four-stage route to post-quantum readiness. Discovery covers where vulnerable cryptography and trust dependencies sit across applications, cloud, APIs, PKI, key management and third parties, and a readiness evaluation tests crypto-agility across technology, identities, certificates, key wrapping, BYOK and backup and recovery. The outputs include an executive risk and investment case.
CGI then builds a consolidated CBOM covering algorithms, keys, certificates and dependencies across IT, OT, cloud, networks and third parties, and ranks exposure in a quantum risk heatmap and priority register based on data sensitivity, harvest now, decrypt later risk, criticality and remediation complexity. The migration roadmap sequences work against business risk, regulatory pressure and vendor readiness, and CGI can support PQC pilots including hybrid TLS, PKI changes and HSM integration. CGI describes itself as one of the first NCSC-assured consultancies for PQC discovery and migration planning, which carries weight with UK public sector and critical infrastructure buyers.
6. Kyndryl — Quantum Safe Assessment Tied To A Zero Trust Framework
Kyndryl, the New York infrastructure services company, launched its Quantum Safe Assessment in December 2025. The service maps the encryption protecting services, applications, systems, networks and data across the enterprise and produces a Cryptographic Bill of Materials. It then flags the most exposed systems and third-party interfaces, such as payment gateways, customer databases, cloud infrastructure and mainframes.
Prioritization is based on data sensitivity, business impact and the estimated timeline of quantum threats, and the output is a phased roadmap toward quantum-resistant encryption and full cryptographic agility. Kyndryl ties quantum readiness to its Zero Trust Adoption Framework across identity, endpoints, networks and data, so PQC planning fits into a broader security modernization program. After the assessment, Kyndryl Consult can help define, implement and manage the strategy. Its infrastructure and mainframe background makes it a natural fit for banks, insurers and airlines with long-lived core systems.
7. Encryption Consulting — Eight-Stage PQC Advisory From A PKI And Key Management Specialist
Encryption Consulting is a Texas-based firm that specializes in PKI, HSMs and key management, and its PQC advisory service reflects that focus. It scans the environment to find quantum-vulnerable certificates, algorithms, protocols and keys, builds an inventory of cryptographic assets and assesses quantum risk for each one, along with governance, data classification and alignment with NIST guidance on ML-KEM, ML-DSA and SLH-DSA.
Its project plan runs through eight stages: kickoff, discovery, risk assessment, strategy, roadmap design, proof of concept, implementation planning and crypto-agility enablement. Further offerings include hybrid cryptography deployment, proof-of-concept testing, crypto-agile PKI architecture and key management redesign, and the firm’s CBOM Secure product supports discovery. Encryption Consulting estimates that migration typically takes 12 to 36 months. Because certificates and PKI are where many PQC programs stall, a specialist that lives in that layer is a practical alternative to a large consultancy.
8. PQShield — Algorithm-Level PQC Advisory From A Team That Helped Shape The Standards
PQShield is a post-quantum cryptography company with offices in Oxford, Paris, Amsterdam, New York, Campbell in California and Tokyo. It says its team helped shape the first NIST PQC standards, and it sells software libraries such as PQCryptoLib and PQMicroLib for memory-constrained devices, along with hardware products including a secure coprocessor, a root-of-trust system and performance accelerators.
PQShield also runs a consulting engagement in four steps: discuss, evaluate where cryptography is at risk, design and implement. That makes it unusual on this list. Where the large consultancies focus on enterprise inventories and migration programs, PQShield is strongest when the question is how to build ML-KEM or ML-DSA correctly into a product, such as a chip, an embedded device, a smart card or an OpenSSL-based application. Semiconductor, automotive, IoT and defense suppliers that must ship quantum-safe products should consider it first.
9. IDEMIA — Post-Quantum Consulting For Cards, Secure Elements And HSMs
IDEMIA is a French secure payments and identity company formed from Oberthur Technologies and Morpho. Its Post-Quantum Security Consulting, part of the IDEMIA Sphere cybersecurity offer, covers cryptographic risk assessment of protocols, key management, trust models and algorithm choices, long-term cryptographic design that balances security with performance and hardware limits, and migration and implementation.
The migration work includes a roadmap, algorithm selection, crypto-agile mechanisms and support for rollout across cloud, embedded systems, secure elements and HSMs, including hybrid modes and integration with IDEMIA’s Sphere CryptoLib and Sphere HSM. Targeted studies cover protocol hardening and performance tuning. IDEMIA cites more than 190 cryptography patent families and over 100 Common Criteria certified embedded products, and in 2025 it launched a library of classical and post-quantum algorithms. Banks, card issuers, telecom operators and government ID programs with hardware in the field are the natural fit.
Farcaster Consulting Group is a boutique firm based in Bellevue, Washington that offers post-quantum cryptography transition services. Its work starts with a cryptographic inventory and risk assessment that finds where classical algorithms such as RSA, ECC and Diffie-Hellman are deployed and evaluates their exposure to quantum threats.
From there, Farcaster builds a prioritized migration roadmap toward NIST-standardized post-quantum algorithms, reviews crypto-agility to decide whether systems can be updated in place or need re-architecture, and provides hands-on implementation guidance to engineering teams. That last point matters for software companies whose developers need direct help with library choices and protocol changes rather than a strategy deck. Farcaster suits mid-sized organizations and engineering-led teams that want senior attention and a focused scope rather than a multi-year transformation program.
How To Choose A Post-Quantum Cryptography Consulting Firm
PQC migration is a multi-year program, so the first partner you pick shapes the rest of the work. Ask these questions before you commit.
How Will They Build Our Cryptographic Inventory?
A cryptographic inventory, often delivered as a CBOM, is the foundation of every PQC program. Ask whether the firm scans source code, binaries, network traffic, certificates and key stores, and how it covers systems without source code access, third-party software and OT. An inventory built only from interviews will miss a lot.
How Do They Prioritize What To Fix First?
Good firms rank systems by how long the data must stay confidential, how exposed the system is, how critical it is and how hard it is to change. Data with a long secrecy life, such as health, financial and identity records, should move first because of harvest now, decrypt later risk.
Do They Design For Crypto-Agility?
NIST is still adding standards, including FN-DSA as FIPS 206. Crypto-agility means you can swap algorithms through configuration and policy rather than code rewrites. Ask how the firm will centralize cryptographic policy, certificates and key management so the next change is easier than this one.
Will They Test Hybrid Deployments Before Rollout?
Most organizations will run hybrid classical and post-quantum schemes during the transition. ML-KEM and ML-DSA keys and signatures are larger than RSA and ECC equivalents, which can affect performance and older devices. Ask for a pilot plan that tests TLS, VPNs, code signing and PKI in your environment before broad rollout.
How Does This Fit Our Wider Security Program?
PQC touches PKI, identity, cloud, vendors and compliance. Choose a firm that can work with your existing cybersecurity consulting and risk teams, and make sure third-party software vendors are included in the plan.
Conclusion
NIST’s FIPS 203, 204 and 205 have turned post-quantum cryptography from research into a planning requirement. Large enterprises will get the most from IBM, Accenture, Deloitte, Capgemini, CGI or Kyndryl, which can run discovery and migration across thousands of systems. Encryption Consulting and Farcaster offer focused help for organizations that want a specialist, while PQShield and IDEMIA are the strongest choices for building PQC into products and hardware. Whichever firm you choose, start with a complete cryptographic inventory and design for crypto-agility, because the standards will keep moving.
