Cryptographic Infrastructure
Enterprise encryption architecture, cryptographic inventories, key lifecycle governance, and practical crypto-agility planning.
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MISSION-CRITICAL INFRASTRUCTURE CONSULTING
Closing the Gap Between Business Objectives and Architecture & Engineering.
Security Infrastructure Built for What Comes Next. GC Solutions turns business priorities into architecture and engineering decisions that protect cryptographic keys, communications, and critical systems.
Service-disabled veteran-owned Omaha, Nebraska
CRYPTOGRAPHY◆PKI◆HSM◆KEY MANAGEMENT◆CYBERSECURITY◆PCI-DSS◆CRYPTO-AGILITY◆POST-QUANTUM SECURITY◆CRYPTOGRAPHY◆PKI◆HSM◆KEY MANAGEMENT◆CYBERSECURITY◆PCI-DSS◆CRYPTO-AGILITY◆POST-QUANTUM SECURITY◆
THE OPERATING MODEL
Business objectives translated into architecture and engineering.
GC Solutions closes the gap between executive intent and technical execution—bringing cryptographic architecture, engineering, governance, compliance, risk, and business priorities into one decision framework.
01Technical Architecture→
02Governance→
03Compliance→
04Risk→
05Business Objectives
CORE CAPABILITIES
Cryptographic systems designed to be understood, governed, and changed.
Specialized advisory across the technical and organizational layers that determine whether enterprise security controls work in practice.
PKI & Certificate Management
Trust architecture, certificate lifecycle management, machine identity, and enterprise PKI strategy.
Learn moreHSM & Key Management
HSM and KMS architecture, key custody, secure ceremonies, rotation, access control, and lifecycle operations.
Learn morePost-Quantum Cryptography
Cryptographic discovery, dependency mapping, vendor readiness, hybrid approaches, and migration planning for evolving standards.
Learn moreFintech & Payment Security
Cryptographic controls for payment systems, financial technology platforms, and other regulated environments.
Learn moreCompliance & Audit Readiness
Clear evidence, ownership, procedures, and control alignment for PCI-DSS, NIST, and enterprise security reviews.
Learn moreTelecommunications & Secure Comms
Resilient communications architecture and operational thinking for mission-critical connectivity.
Learn moreCybersecurity Strategy
Security architecture connected to governance, organizational risk, vendor decisions, and business objectives.
Learn moreTHE EXECUTIVE PROBLEM
Security Complexity Is Becoming a Business Problem.
Modern organizations do not simply need stronger encryption. They need visibility, ownership, governance, and the ability to adapt cryptographic infrastructure without losing control of operations.
Certificate growth, cloud services, HSM estates, key lifecycles, regulatory expectations, legacy platforms, and post-quantum planning now intersect. GC Solutions turns that complexity into a structured path forward.
Assess your current posture →GREENHILL COMPOUND SOLUTIONS
Enterprise Cryptography & Secure Communications
Specialized architecture, advisory, and readiness.
GC Solutions helps regulated and mission-critical organizations address cryptographic infrastructure, HSMs, key management, PKI, certificate lifecycles, PCI-DSS controls, crypto-agility, post-quantum planning, telecommunications, and secure communications.
About GC Solutions01 / UNDERSTANDDiscover the environment
→02 / DECIDEArchitect the target state
→03 / OPERATEGovern and modernize
HOW WE WORK
Clear decisions for systems that cannot afford ambiguity.
The GC Solutions approach is disciplined and evidence-led: know what exists, define who owns it, align controls to real requirements, and build an architecture that can adapt without losing trust.
01DISCOVER
02DESIGN
03GOVERN
04MODERNIZE
HOW GC SOLUTIONS HELPS
From complex security questions to structured decisions.
Engagements are shaped around the architecture, governance, compliance, and readiness questions leaders need to resolve.
Cryptographic Architecture Advisory
Clarify the systems, trust boundaries, algorithms, and governance behind enterprise cryptographic services.
PKI & Certificate Strategy
Define certificate ownership, lifecycle controls, machine identity priorities, and modernization paths.
HSM / KMS Architecture
Evaluate custody models, access controls, integration patterns, lifecycle operations, and technology fit.
Crypto-Agility Assessments
Identify dependencies and decision points that affect an organization’s ability to change algorithms or providers.
PCI-DSS Cryptographic Readiness
Translate cryptographic control expectations into evidence, procedures, and architecture decisions.
Post-Quantum Readiness
Build a practical path from cryptographic inventory to prioritized migration planning.
Vendor & Technology Strategy
Compare capabilities, integration constraints, governance implications, and operational fit.
Cybersecurity Architecture
Connect technical design to risk, resilience, compliance, and business requirements.
Compliance & Audit Preparation
Improve control clarity, ownership, documentation, and evidence readiness before formal review.
Strategic Technology Consulting
Turn complex infrastructure choices into structured executive decisions and actionable plans.
FOUNDER & PRINCIPAL ARCHITECT
Marquez Greenhill
Marquez Greenhill is the Founder & Principal Architect of GC Solutions, a decorated U.S. Air Force veteran, and a technology and security leader with more than 15 years of experience across enterprise cryptography, secure communications, financial technology, defense systems, and mission-critical infrastructure. His defining strength is closing the gap between business objectives and architecture and engineering—translating complex requirements into practical systems, operating models, and partner strategies that executives, engineers, compliance teams, and vendors can act on.
His background includes senior cryptographic engineering and key-custody responsibilities in financial technology; HSM, KMS, PKI, certificate-lifecycle, NIST, and PCI-DSS work; NC3, MILSATCOM, tactical communications, and mission-systems roles; and leadership of complex infrastructure and technology programs. Through GC Solutions, he applies that cross-domain experience to vendor selection, solution alignment, operational readiness, crypto-agility, and post-quantum planning.
INSIGHTS & PERSPECTIVES
Technical subjects, explained for real decisions.
Verified public writing from GC Solutions founder and principal architect Marquez Greenhill on cryptographic infrastructure, assurance, and emerging change.
LINKEDIN INSIGHT01
KEY MANAGEMENT
KMS vs. HSM: What’s the Difference?
A practical distinction between managing cryptographic keys and protecting high-assurance key material in hardware.
Read original postLINKEDIN INSIGHT02
POST-QUANTUM
Preparing Financial Institutions for the Quantum Threat
An executive perspective on quantum-era planning for institutions with long-lived data and complex cryptographic dependencies.
Read original postLINKEDIN INSIGHT03
COMPLIANCE
Understanding Common Criteria
Why security product evaluation standards matter when organizations assess assurance, controls, and technology choices.
Read original postLINKEDIN INSIGHT04
GC SOLUTIONS
Enterprise Cryptography & Secure Communications
A view of GC Solutions’ focus on cryptographic infrastructure, communications resilience, and practical execution.
Read original postGC SOLUTIONS FRAMEWORK
The Cryptographic Security Lifecycle
A repeatable way to move from unknown exposure to governed, adaptable infrastructure.
- 01
DISCOVER
Know the assets, algorithms, keys, certificates, and dependencies in scope.
- 02
ASSESS
Evaluate exposure, ownership, lifecycle controls, and operational constraints.
- 03
ARCHITECT
Define trust boundaries, custody models, controls, and integration patterns.
- 04
IMPLEMENT
Translate architecture into secure, supportable operating practices.
- 05
GOVERN
Maintain ownership, evidence, policy alignment, and accountable decisions.
- 06
MODERNIZE
Adapt algorithms, platforms, and practices without losing control of the system.
KeysCertificatesHSMsPKIPoliciesComplianceCrypto-AgilityPQC
POST-QUANTUM READINESS
Is Your Organization Ready for the Post-Quantum Era?
Preparation starts before algorithm replacement. Organizations need to know where cryptography lives, which information must remain protected for years, how certificates and vendors are affected, and whether existing systems can change safely.
Start a PQC Readiness ConversationBuild security infrastructure the organization can understand, govern, adapt, and trust.
GC SOLUTIONS / OPERATING PRINCIPLESECURITY DOMAINS
Where trust becomes infrastructure.
01Enterprise cryptography
02HSM & key management
03PKI & machine identity
04Secure communications
05Fintech security
06Compliance & audit readiness
07Crypto-agility
08Post-quantum readiness
CryptographyKeys, HSMs, PKI, certificates, and trust architecture
ComplianceControl clarity, evidence, ownership, and audit readiness
ContinuitySecure communications and mission-critical infrastructure
MEASURE
How ready is your cryptographic infrastructure?
Use a seven-question educational assessment to identify the next conversation.
Start the assessmentUNDERSTAND
Turn technical language into executive clarity.
Search concise definitions for the terms shaping cryptographic decisions.
Explore the glossarySTART WITH A CONVERSATION
Let’s Talk About Your Security Infrastructure.
Whether you are evaluating cryptographic architecture, preparing for a compliance review, modernizing key management, or planning for post-quantum security, GC Solutions can help frame the path forward.