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Volume 1

The Sovereign Identity Engine

Mathematical Foundations and Cryptographic Building Blocks for Non Custodial Systems

Your identity is only as secure as the math it is built upon.

Strategic Objectives

• Master the discrete mathematics behind elliptic curve cryptography.

• Implement zero-knowledge proofs for privacy-preserving verification.

• Architect collision-resistant hashing structures for immutable identifiers.

• Design secure digital signature schemes without relying on third parties.

The Core Challenge

In a world of centralized data silos and frequent breaches, developers lack a specialized guide to the low-level primitives required for true digital autonomy.

01

The First Principles of Sovereignty

Defining the Non-Custodial Mathematical Model
You will begin by understanding the philosophical and technical requirements of self-sovereignty. This chapter establishes why mathematical primitives must replace central authorities, setting the stage for every technical component you will master in the following pages.
Understanding Sovereignty in the Digital Realm
The philosophical roots of self-sovereignty

Explore the conceptual underpinnings of personal autonomy in identity management, emphasizing why control must shift from centralized institutions to the individual.

Limitations of Custodial Systems
Why central authorities fail in the modern landscape

Analyze the weaknesses of traditional identity systems, including single points of failure, privacy risks, and the inability to enforce true individual control.

Mathematical Foundations for Non-Custodial Control
Primitives that enable trust without intermediaries

Introduce the core cryptographic tools and mathematical constructs—such as public-key cryptography, hash functions, and zero-knowledge proofs—that form the backbone of non-custodial identity systems.

02

Number Theory Fundamentals

The Arithmetic of Secure Systems
You need to master the behavior of integers and prime numbers to understand how cryptographic keys are generated. This chapter provides the essential mathematical vocabulary required for you to grasp the complexity of modern encryption.
Understanding Integers and Divisibility
The Building Blocks of Cryptographic Arithmetic

Explore the properties of integers, divisibility rules, and the foundational operations that underpin modular arithmetic, which is central to key generation in encryption systems.

Prime Numbers and Their Significance
Why Primes Power Secure Systems

Delve into prime numbers, their unique properties, and their critical role in generating cryptographic keys, including how prime factorization ensures computational security.

Greatest Common Divisors and Coprimality
Ensuring Safe Modular Relationships

Understand the concepts of greatest common divisors, coprime integers, and Euclid’s algorithm, which are essential for creating secure key relationships and avoiding vulnerabilities in cryptographic protocols.

03

Finite Fields and Modular Arithmetic

The Boundaries of Cryptographic Computation
You will explore the finite mathematical structures where cryptographic operations take place. Understanding these fields is vital for you to ensure that your identity calculations remain consistent, predictable, and secure from overflow errors.
Why Cryptography Lives in Finite Worlds
Computation Under Explicit Limits

This section introduces the philosophical and computational necessity of finiteness in cryptographic systems. It explains why identity engines cannot rely on continuous mathematics and instead operate inside bounded algebraic universes where every operation is defined, predictable, and closed. The reader is guided to see finite fields not as abstract curiosities, but as the formal boundaries that prevent ambiguity, overflow, and computational drift in sovereign identity calculations.

Modular Arithmetic as the Language of Boundaries
Clock Arithmetic and Deterministic Reduction

This section develops modular arithmetic as the foundational reduction mechanism that keeps cryptographic computations within fixed numerical ranges. It explains congruence, residue classes, and modular reduction as tools that transform unbounded integer operations into controlled, cyclic structures. The discussion connects modular arithmetic directly to overflow control and deterministic reproducibility in non-custodial identity systems.

Prime Fields and the Architecture of Security
Why Primality Creates Invertibility

This section explores fields constructed from prime moduli and explains why prime numbers ensure that every non-zero element has a multiplicative inverse. It clarifies how this property guarantees stable division operations, which are essential in signature schemes and key derivation. The reader learns why cryptographic systems overwhelmingly choose prime-based structures and how this choice enforces algebraic consistency in identity verification processes.

04

The Discrete Logarithm Problem

The One-Way Function of Identity
You will investigate the computational hardness that protects private keys. By understanding why this problem is difficult to solve, you will gain confidence in the mathematical 'moat' that keeps your sovereign identity safe from brute-force attacks.
From Exponentiation to Irreversibility
Why Going Forward Is Easy and Going Back Is Hard

This section introduces exponentiation in modular arithmetic as a computationally efficient operation and contrasts it with the inverse task of recovering exponents. It frames the discrete logarithm problem as a structural asymmetry: multiplication and exponentiation compose smoothly, yet reversing them in finite groups appears intractable. The discussion emphasizes how this asymmetry becomes the core one-way function underlying non-custodial identity systems.

Algebraic Landscapes for Identity
Finite Fields and Cyclic Groups as Cryptographic Terrain

Here the chapter situates the discrete logarithm problem within specific algebraic structures: multiplicative groups of finite fields and cyclic groups generated by primitive elements. The section explains why group structure matters, how generators define identity anchors, and why carefully chosen parameters prevent structural shortcuts. Readers see how sovereign identity keys are embedded inside well-defined mathematical worlds.

Measuring Hardness
Algorithms That Try—and Why They Struggle

This section surveys known algorithmic strategies for solving discrete logarithms, from brute force and baby-step giant-step to index calculus methods. Rather than detailing implementation, it focuses on growth rates, computational complexity, and how security parameters scale against adversarial capability. The aim is to make clear that hardness is not mystical but quantified, modeled, and continuously stress-tested.

05

Cryptographic Hash Functions

Ensuring Data Integrity and Fingerprinting
You will learn how to condense complex identity data into unique, fixed-size strings. This chapter teaches you how to ensure that any tampering with a user's identity data is immediately detectable through mathematical fingerprints.
From Identity Records to Mathematical Fingerprints
Why Non-Custodial Systems Need Deterministic Compression

This section introduces the core problem of representing complex, structured identity data—names, credentials, biometric references, public keys—as a single, fixed-size mathematical fingerprint. It frames hash functions as deterministic compression mechanisms that transform arbitrary-length input into compact outputs suitable for decentralized verification. The narrative emphasizes why sovereign identity systems require self-verifiable integrity rather than reliance on centralized custodians.

Security Properties That Make Fingerprints Trustworthy
Preimage Resistance, Second Preimage Resistance, and Collision Resistance

This section explains the three core security guarantees that distinguish cryptographic hash functions from ordinary checksums. It interprets preimage resistance as protection against identity reconstruction, second preimage resistance as protection against substitution attacks, and collision resistance as protection against duplicate identities masquerading as distinct records. The focus is on how each property underpins tamper detection in sovereign identity architectures.

Avalanche and Sensitivity
Why One Bit of Change Breaks the Illusion

This section explores the avalanche effect and statistical diffusion. It demonstrates how even a one-bit alteration in identity data—such as a modified credential attribute—produces a radically different hash output. The section connects this property to practical tamper detection, explaining why hash comparisons provide immediate evidence of data manipulation in distributed systems.

06

Merkle Trees and Sparse Accumulators

Efficient Verification of Identity Claims
You will discover how to organize identity hashes into hierarchical structures. This allows you to provide proofs of membership for specific attributes without sharing the entire identity dataset, optimizing both speed and privacy.
From Flat Hash Lists to Hierarchical Commitments
Why Identity Systems Need Structured Aggregation

This section motivates the transition from storing independent identity hashes to organizing them into hierarchical commitments. It explains the scalability and privacy limitations of flat hash sets and introduces the conceptual leap: compressing large identity datasets into a single root commitment that preserves verifiability without exposing underlying data.

Anatomy of a Merkle Tree
Hash Pairing, Binary Structure, and Deterministic Roots

This section explains how leaves, internal nodes, and the root are constructed through iterative hashing. It explores why binary trees are common, how ordering affects determinism, and how cryptographic hash properties ensure collision resistance and tamper evidence within the structure.

Merkle Proofs as Minimal Disclosure Mechanisms
Efficient Membership Verification Without Full Revelation

This section details how authentication paths enable selective disclosure. It shows how a verifier can reconstruct the root from a small set of sibling hashes and a target leaf, proving membership in logarithmic time while revealing nothing about unrelated attributes in the identity dataset.

07

Elliptic Curve Theory

High-Efficiency Public Key Cryptography
You will dive into the geometry of elliptic curves to understand why they offer more security with smaller key sizes. This is crucial for you when building identity systems that must run on resource-constrained mobile devices.
From Classical Public Keys to Compact Cryptography
Why Identity Systems Demand Smaller Keys

This section frames the limitations of classical public key systems in mobile and embedded environments. It contrasts integer-factorization and discrete-logarithm systems with elliptic curve constructions, explaining why equivalent security can be achieved with dramatically smaller key sizes. The discussion connects these efficiency gains directly to non-custodial identity wallets, battery life, bandwidth constraints, and secure enclave limitations.

The Geometry Behind the Algebra
Understanding Elliptic Curves as Algebraic Structures

This section introduces elliptic curves as geometric objects defined by cubic equations, then transitions to their algebraic interpretation over finite fields. It explains how the visual intuition of point addition on a curve becomes a rigorously defined group operation. The goal is not abstract theory for its own sake, but to reveal why the curve structure produces hard mathematical problems suitable for cryptography.

The Elliptic Curve Discrete Logarithm Problem
Where Security Actually Lives

Security in elliptic curve systems rests on the hardness of the elliptic curve discrete logarithm problem. This section explains scalar multiplication, why reversing it is computationally infeasible, and how this asymmetry forms the backbone of secure key exchange and digital signatures. The treatment emphasizes complexity assumptions and why smaller parameters remain secure compared to classical discrete logarithm systems.

08

The Edwards Curve Advantage

Optimizing for Performance and Security
You will examine specialized curve shapes that prevent side-channel attacks and simplify implementation. This chapter guides you in choosing the most robust curves for real-world sovereign identity applications.
Introduction to Edwards Curves
Why Curve Choice Shapes Security and Efficiency

Explore the evolution of elliptic curves in cryptography, emphasizing how Edwards curves emerged as a solution for both performance optimization and resistance to implementation attacks in identity systems.

Mathematical Foundations
Understanding the Algebra Behind Edwards Curves

Dive into the defining equations of Edwards curves, explain their group structure, addition laws, and contrast their simplicity with traditional Weierstrass curves for practical cryptographic operations.

Performance Advantages in Implementation
Speed, Efficiency, and Computational Simplicity

Analyze why Edwards curves enable faster arithmetic, reduce computational overhead, and simplify point addition and doubling, making them ideal for real-time, resource-constrained identity systems.

09

Digital Signature Algorithms

The Mathematics of Non-Repudiation
You will learn the mechanics of how a private key signs a message. This allows you to build systems where users can prove their intent and authorize actions without ever revealing their underlying secrets.
Foundations of Digital Signatures
Why Signatures Matter in Non-Custodial Systems

Introduce the concept of digital signatures, their role in proving ownership and intent, and why they are essential for decentralized identity systems. Highlight the distinction between authentication, integrity, and non-repudiation.

Mathematical Principles Behind Signatures
Modular Arithmetic, Hash Functions, and Key Pairs

Explore the mathematics that enable digital signatures, including one-way functions, modular arithmetic, and the generation of public-private key pairs. Explain how these ensure that only the owner can sign a message.

How Private Keys Generate Signatures
Step-by-Step Mechanics of Signing

Detail the process by which a private key produces a digital signature for a message. Include discussion on message hashing, signature calculation, and the mathematical guarantees that prevent forgery.

10

Schnorr Signatures

Simplicity and Linearity in Identity
You will explore the efficiency of Schnorr signatures, which allow for signature aggregation. This is a key skill for you if you intend to build multi-party identity schemes where several actors must approve a single transaction.
Foundations of Schnorr Signatures
Mathematical Principles Underpinning Identity Proofs

Introduce the core mathematics behind Schnorr signatures, including modular arithmetic, discrete logarithms, and elliptic curve adaptations, to ground readers in the mechanisms that enable compact and verifiable proofs of identity.

Signature Generation and Verification
Step-by-Step Construction and Validation

Detail the process of creating a Schnorr signature and verifying it, emphasizing its simplicity and linearity compared to other signature schemes, while highlighting the implications for non-custodial identity systems.

Aggregation and Multi-Party Approvals
Efficiently Combining Multiple Signatures

Explore the ability of Schnorr signatures to aggregate multiple signatures into one, illustrating how this supports multi-party identity schemes where several participants approve a single transaction without bloating data size.

11

The ECDSA Standard

Implementing Industry-Standard Identity
You will master the most widely used elliptic curve signature scheme. Understanding ECDSA ensures that the sovereign identity tools you build are compatible with existing blockchain and web infrastructures.
Foundations of Elliptic Curve Cryptography
Why Elliptic Curves Matter for Sovereign Identity

Introduce elliptic curves and their mathematical properties, emphasizing why they provide strong security with compact key sizes. Explain how these properties underpin identity systems and non-custodial frameworks.

Understanding ECDSA Mechanics
From Keys to Signatures

Break down the ECDSA workflow step by step, including key generation, signing, and verification. Highlight the role of randomness and modular arithmetic in securing digital signatures for identity proofs.

Security Properties and Vulnerabilities
Ensuring Robust Identity Authentication

Analyze the security guarantees of ECDSA and common pitfalls, such as weak randomness or repeated nonces. Relate these issues to practical risks in blockchain and decentralized identity systems.

12

Public Key Infrastructure (PKI) Refined

Removing the Certificate Authority
You will re-evaluate traditional PKI through a non-custodial lens. This chapter shows you how to manage trust and key distribution without falling back on the centralized models you are trying to avoid.
Limitations of Centralized PKI
Understanding the Risks of Certificate Authorities

Examine the structural weaknesses of traditional PKI, including single points of failure, trust bottlenecks, and exposure to systemic compromise. Emphasize why centralized authorities are antithetical to non-custodial identity systems.

Trust Without a Central Authority
Decentralized Models and Web of Trust

Introduce alternative frameworks for distributing trust, such as decentralized ledgers, peer-to-peer key validation, and web-of-trust approaches. Show how these methods reduce reliance on centralized intermediaries.

Cryptographic Anchors for Sovereign Identity
Mathematical Guarantees Over Institutional Guarantees

Detail how cryptographic primitives, including public/private key pairs, digital signatures, and hash-based attestations, can replace institutional validation. Explain mechanisms for establishing verifiable claims without certificates.

13

Key Derivation Functions

Generating Identity from Entropy
You will learn how to turn a single seed or password into a vast tree of cryptographic keys. This enables you to help users manage multiple identity personas from a single recovery phrase.
From Raw Entropy to Deterministic Identity
Why One Secret Must Become Many

Introduces the problem of identity scalability in non-custodial systems. Explains how a single high-entropy seed can serve as the root of an entire cryptographic identity structure. Frames key derivation functions as the mathematical bridge between unpredictable entropy and structured, reproducible identity trees.

The Mathematics of Key Stretching
Slowing Down Attackers Without Slowing Down Users

Explores how key derivation functions transform passwords into hardened cryptographic keys through computational cost, memory hardness, and iteration. Discusses why stretching is essential for human-memorable secrets and how parameter tuning balances usability and brute-force resistance in identity systems.

Pseudorandom Expansion and Domain Separation
Ensuring Independence Across Identity Contexts

Examines how pseudorandom functions expand a single seed into multiple independent keys. Introduces the principle of domain separation to prevent cross-context key reuse, enabling distinct personas, applications, and trust domains to coexist safely under one master secret.

14

Commitment Schemes

Binding Data Without Disclosure
You will discover how to 'lock' a value in a mathematical envelope. This allows you to build systems where a user can commit to a piece of information now and reveal it later, ensuring the data hasn't been changed in the interim.
The Cryptographic Envelope
Why Sovereign Systems Need Sealed Assertions

This section introduces the core intuition behind commitment schemes as digital envelopes: a user locks a value today and proves later that it has not changed. Framed within non-custodial identity systems, the discussion connects commitments to delayed disclosure, minimizing trust while preserving autonomy. The section clarifies the distinction between hiding information and binding oneself to it.

Security as a Two-Sided Guarantee
Balancing Hiding and Binding

This section examines the dual security guarantees that define commitment schemes. Hiding ensures that no observer can extract the committed value before revelation, while binding prevents the committer from changing it later. The section explores computational versus unconditional variants of these properties and explains why trade-offs matter in decentralized identity infrastructures.

From Hash Locks to Algebraic Commitments
Concrete Constructions and Their Assumptions

This section surveys practical constructions, beginning with hash-based commitments and moving toward number-theoretic and group-based designs. It explains how randomness (often called the opening value) prevents brute-force recovery and how algebraic structure enables advanced capabilities. The mathematical assumptions underpinning each construction are connected to their role in secure identity systems.

15

Zero-Knowledge Proofs (ZKP)

Proving Truth Without Sharing Data
You will master the crown jewel of identity privacy. This chapter teaches you how to allow a user to prove they are over 18, or have a certain credit score, without revealing their birthdate or exact financial balance.
From Disclosure to Demonstration
Why Identity Systems Must Move Beyond Data Exposure

This section reframes identity verification as a logical problem rather than a data-sharing problem. It explains why traditional identity systems require excessive disclosure and how zero-knowledge proofs redefine verification as the ability to demonstrate the truth of a statement without revealing the underlying data. The narrative connects this shift directly to sovereign identity architectures and non-custodial design principles.

The Three Pillars of Zero Knowledge
Completeness, Soundness, and Zero-Knowledge as Security Guarantees

This section formalizes the mathematical foundations of zero-knowledge proofs by unpacking the three defining properties: completeness, soundness, and zero-knowledge. It explains how these properties create enforceable guarantees in identity systems, ensuring that honest users can prove claims, dishonest users cannot cheat, and verifiers learn nothing beyond the validity of the claim.

Interactive vs Non-Interactive Proofs
From Cryptographic Dialogue to Portable Credentials

This section compares interactive zero-knowledge protocols with non-interactive constructions and explains why non-interactive zero-knowledge (NIZK) is essential for scalable digital identity systems. It introduces the Fiat–Shamir transformation and demonstrates how proofs can become portable artifacts embedded inside verifiable credentials and blockchain transactions.

16

zk-SNARKs and zk-STARKs

Succinct Non-Interactive Identity Proofs
You will delve into the advanced math required for non-interactive proofs. This is vital for you to build scalable systems where identity verification can happen instantly and asynchronously on a global scale.
From Interaction to Broadcast: Why Identity Needs Non-Interactivity
Asynchronous Trust in a Stateless World

This section reframes zero-knowledge proofs as infrastructure for sovereign identity systems that cannot rely on synchronous verifier–prover dialogue. It explains why non-interactive proofs are essential for global, permissionless environments, where identity attestations must be generated once and verified anywhere. The narrative emphasizes the shift from conversational cryptography to publicly verifiable mathematical artifacts.

Arithmetic Circuits and Constraint Systems
Encoding Identity Claims as Algebra

Here the chapter dives into the algebraic backbone of zk systems: representing identity predicates as arithmetic circuits and Rank-1 Constraint Systems. Readers explore how statements such as age thresholds, credential possession, or uniqueness constraints become polynomial relations over finite fields. The section connects circuit expressiveness to scalability and proof size.

zk-SNARKs: Succinctness Through Structured Cryptography
Pairings, Trusted Setups, and Verification Efficiency

This section analyzes zk-SNARK constructions, focusing on polynomial commitments, elliptic curve pairings, and the transformation from interactive proofs into succinct non-interactive ones. It explains the role of trusted setup ceremonies and their implications for sovereign identity engines, where toxic waste risks must be evaluated against performance gains.

17

Pairing-Based Cryptography

Mapping Groups for Advanced Identity Functions
You will study bilinear maps, which enable sophisticated features like identity-based encryption and short signatures. This broadens your toolkit for solving complex coordination problems in decentralized networks.
Why Bilinear Maps Matter for Sovereign Identity
From Simple Signatures to Composable Trust Primitives

This section frames pairing-based cryptography as a structural upgrade to the cryptographic toolkit of non-custodial systems. Rather than treating pairings as abstract algebraic curiosities, it positions them as enablers of identity-native cryptography—allowing identities themselves to function as public keys, enabling aggregation, delegation, and compact attestations. The narrative emphasizes why decentralized identity architectures require richer algebraic relationships than traditional discrete-log systems provide.

The Algebra of Pairings
Groups, Bilinearity, and Non-Degeneracy

This section introduces the mathematical structure underlying pairing-based systems: cyclic groups of prime order, efficiently computable bilinear maps, and the critical properties of bilinearity, non-degeneracy, and computability. It explains how mapping between groups creates a bridge that preserves exponent relationships, enabling verification equations impossible in ordinary group settings. The focus is conceptual clarity—why these properties unlock new identity constructions.

From Weil and Tate to Modern Curves
Elliptic Curves as Engines of Mapped Trust

This section traces how pairings arise from elliptic curve theory, highlighting the transition from classical Weil and Tate pairings to practical constructions on pairing-friendly curves. It explains embedding degree, security tradeoffs, and why curve selection determines both performance and attack resistance. The emphasis is on engineering judgment: choosing curves that sustain sovereign systems over long time horizons.

18

Threshold Cryptography

Distributed Identity Control
You will learn how to split a private key into multiple shards. This allows you to design social recovery systems where a user can lose their device but still regain their identity through a quorum of trusted friends.
Introduction to Threshold Cryptography
Why Splitting Secrets Strengthens Identity Security

Explore the fundamental idea behind threshold cryptography: dividing a private key into multiple parts to prevent a single point of failure, and how this approach enhances the resilience of identity systems.

Mathematical Foundations of Key Sharding
Polynomials, Finite Fields, and Secret Reconstruction

Dive into the mathematics that enables secret splitting, including polynomial interpolation and modular arithmetic, explaining how any subset of shards can reconstruct the original secret while fewer reveal nothing.

Designing Threshold-Based Identity Recovery
From Device Loss to Social Recovery

Learn how to structure a social recovery system using threshold cryptography, defining quorum sizes, assigning trusted participants, and balancing security with usability.

19

Homomorphic Encryption in Identity

Computing on Encrypted Identity Data
You will explore the cutting edge of privacy by learning how to perform calculations on identity data while it remains encrypted. This protects the user's data even from the servers processing their identity claims.
The Privacy Imperative in Digital Identity
Why computation on encrypted data matters

Introduce the risks of exposing identity data during verification or computation and motivate homomorphic encryption as a solution that preserves user privacy while enabling server-side processing.

Foundations of Homomorphic Encryption
Mathematical principles behind secure computation

Explain the algebraic structures, encryption schemes, and the concept of performing operations on ciphertexts without decryption. Include distinctions between partial, somewhat, and fully homomorphic encryption.

Architectures for Encrypted Identity Computation
Integrating HE into identity systems

Examine how homomorphic encryption can be incorporated into non-custodial identity platforms, including server-client models, zero-trust environments, and identity verification workflows.

20

Post-Quantum Identity Primitives

Future-Proofing Sovereignty
You will look ahead to the threat of quantum computing. This chapter prepares you to transition your identity systems to lattice-based or hash-based primitives that can withstand the power of future quantum adversaries.
The Quantum Threat Landscape
Understanding the Risks to Identity Systems

Explore how quantum computing threatens current cryptographic methods underpinning non-custodial identity systems. Analyze the specific vulnerabilities of RSA, ECC, and classical hash functions in the context of identity authentication and verifiable credentials.

Foundations of Post-Quantum Cryptography
Mathematical Constructs for Future-Resistant Security

Introduce the primary mathematical frameworks enabling post-quantum security, focusing on lattices, hash-based constructions, multivariate polynomials, and code-based systems. Emphasize their relevance to identity proofs and key management.

Lattice-Based Identity Primitives
Constructing Quantum-Resistant Authentication

Delve into lattice-based schemes, including learning with errors (LWE) and ring-LWE, for secure identity verification. Explain how these primitives enable digital signatures, key exchange, and zero-knowledge proofs in a post-quantum context.

21

The Secure Implementation Lifecycle

From Mathematical Theory to Robust Code
You will conclude by learning how to avoid common implementation pitfalls. This final chapter bridges the gap between the formulas you've studied and the actual code you will write, ensuring your sovereign identity system is practically unbreakable.
Translating Mathematical Constructs into Code
Ensuring Theoretical Integrity in Implementation

Examine how abstract cryptographic primitives and proofs are converted into practical software constructs, focusing on maintaining correctness, precision, and the subtle assumptions that must not be violated in code.

Common Implementation Pitfalls
From Subtle Bugs to Critical Vulnerabilities

Identify frequent errors in coding cryptographic systems, including poor randomness, side-channel exposure, incorrect protocol integration, and improper key management, illustrating their impact on the security of a sovereign identity system.

Secure Coding Practices for Cryptography
Techniques for Resilient and Audit-Ready Code

Explore best practices such as constant-time implementations, careful memory handling, formal verification methods, and comprehensive testing frameworks to produce robust cryptographic code suitable for high-assurance identity systems.

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