ASSURANCE & CUSTODY
HSM and key-management decisions that can stand up to scrutiny.
Clarify custody, access, ceremonies, recovery and operational evidence before control gaps become difficult decisions.
Explore the practiceINDEPENDENT CRYPTOGRAPHIC ASSURANCE & SECURITY ADVISORY
Critical cryptography deserves independent verification.
Evaluate HSM, key management, payment security and PQC evidence into defensible decisions.
Omaha, Nebraska · Serving organizations nationwide
01 / SCOPEDefine the decision
Agree the boundary before interpreting the signals.
02 / EVIDENCERetain the trace
Knowns, gaps and provenance remain visible.
ASSURANCE
PATH
PATH
WHERE THE DECISION GETS HARD
Three areas where confidence depends on the details.
GC Solutions works at the point where technical evidence, accountable ownership and consequential business decisions must meet.
PAYMENT TRUST BOUNDARIES
Tokenization architecture with traceable boundaries.
Examine where trust starts and ends across payment flows, vaults, integrations, cryptographic controls and supporting evidence.
Explore the practiceCRYPTO-AGILE MODERNIZATION
Post-quantum readiness grounded in dependencies.
Turn public-key exposure, vendor claims and long-lived data into a prioritized migration conversation—not a generic deadline.
Explore the practiceTHE ASSURANCE GAP
The risk is rarely only a technical defect.
Critical cryptography fails a decision process when evidence is scattered, ownership is blurred, or an unknown is quietly treated as a pass. An independent review makes the decision path inspectable before a change, review or investment carries more weight.
- A control may exist without current operating evidence.
- Vendor capability can be assumed before it is validated for the environment.
- Key custody, recovery and integration boundaries can become shared-accountability gaps.
- PQC planning can begin with algorithms before the affected dependencies are known.
ADVISORY PORTFOLIO
A defined scope for each consequential question.
Five independent advisory services, built to turn a specific cryptographic question into a more defensible next move.
01INDEPENDENT ASSURANCE
Enterprise Cryptographic Assurance Sprint
An independent, evidence-led review of defined cryptographic infrastructure. Understand material gaps before committing to a change, review or investment.
- Environment and evidence inventory
- HSM and key-management controls review
- Configuration findings and operational risks
- Prioritized recommendations and executive briefing
From $18,000Starting estimate / scope-dependentExplore
02CONTROL & CUSTODY
HSM Security & Key Management Assessment
Evaluate configuration assurance, key lifecycle governance and the operating practices that protect your trust infrastructure.
- Logical access and role separation
- Dual control and split knowledge
- Key ceremonies and operating evidence
- Backup, recovery and retirement review
From $12,500Starting estimate / scope-dependentExplore
03PRIORITIZED MODERNIZATION
Post-Quantum Cryptography Readiness
Identify quantum-vulnerable public-key dependencies, test readiness assumptions, and build a migration plan anchored in business consequence.
- Cryptographic inventory and dependency review
- Crypto-agility and vendor-capability assessment
- Migration prioritization and evidence gaps
- Executive roadmap and decision support
$20,000–$35,000Starting estimate / scope-dependentExplore
04PAYMENT TRUST BOUNDARIES
Payment Security Architecture & Tokenization Advisory
Independent architecture review and cryptographic tokenization implementation consulting for complex payment ecosystems.
- Vault / vaultless model and risk evaluation
- Cryptographic boundary and traceability review
- Access, integration and key-management decisions
- PCI DSS readiness and evidence recommendations
Scoped to your environmentStarting estimate / scope-dependentExplore
05CONTINUING DECISION SUPPORT
Fractional Cryptographic Security Advisor
A defined advisory capacity for leadership teams navigating architecture, vendor choices, governance and migration decisions.
- Architecture and vendor evaluation
- Governance and security decision support
- Migration planning and technical risk review
- Agreed availability and executive communication
From $5,000/monthStarting estimate / scope-dependentExplore
Starting estimates, subject to scope, capacity and a written agreement. These are not binding online offers. No payment is collected on this site.
THE GC SOLUTIONS STANDARD
Evidence before assumptions. Confidence before change.
Independence is a working discipline: product claims are reviewed as inputs, not adopted as conclusions.
INDEPENDENT REVIEW / NOT A LIVE DATA FEED
EvidenceFindingsJudgmentDecision
Provenance retainedUnknowns explicitHuman accountability
ASSESSMENT METHOD
A clear path from question to accountable action.
Each engagement is bounded to the decision at hand. The result is advisory judgment with known limits—not a certification, attestation or full enterprise audit.
- 01
Frame the decision
Agree objectives, boundaries, stakeholders and the evidence needed to answer your business question.
- 02
Examine the evidence
Review approved inventories, control records and architecture. Preserve unknowns rather than treating gaps as a pass.
- 03
Prioritize the exposure
Connect configuration and operational findings to impact, dependencies, confidence and accountable owners.
- 04
Brief the next move
Deliver defensible findings, remediation recommendations and an executive decision path—not unsupported certainty.
FOUNDER & PRINCIPAL ADVISOR
FOUNDER BRIEF
Technical context, translated into accountable decisions.
Marquez “Q” Greenhill founded GC Solutions to provide independent cryptographic assurance and advisory for organizations working through high-trust infrastructure decisions.
His source-grounded background spans national-command communications, financial technology and critical infrastructure programs. The company’s work remains vendor-neutral and scoped to the client’s decision, evidence and operating context.
Read the company and founder profileCRYPTOAGILITY SENTINEL
Evidence-led cryptographic configuration assurance.
CryptoAgility Sentinel is a separate evaluation MVP for generic synthetic-data demonstration and training. Its evidence organization and planning capabilities are distinct from live collection, operational execution or certification.
RESOURCES & FIELD NOTES
Useful context before the first conversation.
CHECKLIST / RESOURCE
Enterprise Cryptographic Exposure & Control Readiness Checklist
A practical, executive-ready way to frame inventory, custody, evidence, dependency and change-readiness questions.
Get the checklistORIGINAL ARTICLE
HSM assurance begins with the evidence trail
A decision framework for examining key-management controls without reducing assurance to a product claim.
Read the articleORIGINAL ARTICLE
Tokenization boundaries are architecture decisions
Questions leaders can use to make payment tokenization responsibilities and trust boundaries more explicit.
Read the articleFREQUENTLY ASKED QUESTIONS
Clarity before scope.
Direct answers about the boundaries of an independent assurance engagement.
What does independent assurance mean here?
A scoped evaluation of available evidence, configuration and controls against agreed requirements. GC Solutions is vendor-neutral: product claims are inputs to examine, not conclusions to accept.
Is an assessment a certification or a full enterprise audit?
No. These engagements provide advisory findings and recommendations within agreed boundaries. They do not issue PCI certifications or attestations, replace a Qualified Security Assessor, or certify a cryptographic module.
How is pricing determined?
Published figures are proposed starting estimates. Systems, evidence availability, integrations, objectives and advisory capacity determine the written scope and price. There is no online purchase or binding offer.
Can you assess different HSM vendor environments?
The founder’s experience spans Futurex, Thales, Utimaco/Atalla and IBM cryptographic platforms. Specific models, versions, evidence access and engagement boundaries are confirmed before work. No vendor authorization or native integration is implied.
Can I submit technical evidence through the contact form?
No. Describe the business challenge at a high level only. Do not send private keys, credentials, HSM exports, card data, customer records or confidential configuration. An approved secure evidence channel is agreed separately.
Is CryptoAgility Sentinel a production enterprise SaaS?
Not currently. It is an evaluation MVP with a generic synthetic-data demonstration and training materials. Read-only evidence organization and planning are distinct from live collection, operational execution or certification.
Do you work outside Omaha?
Yes. GC Solutions serves clients nationwide, with remote, onsite or hybrid delivery agreed for each engagement.
YOUR NEXT STEP
Bring the decision. We’ll help define the evidence path.
Start with a high-level business conversation. Evidence handling, scope and operating boundaries come next.