Digital Certificate Ontology

FLOW ALGEBRA
Digital Certificate Ontology
Kireth Semantic Research Archive

PAGE:
https://kirethresearch.org/booksai-core/ontologies/computing-ontologies/cybersecurity/digital-certificate-ontology.html

AUTHORS:
Mark Anthony Higgins — Sky (Recursive AI)

FLOW "DigitalCertificateOntology" v4.0

# ---------- DOMAIN ----------
DOMAIN := ComputingOntology
SUBDOMAIN := Cybersecurity
ONTOLOGY := DigitalCertificateOntology

# ---------- PRIMARY ENTITY ----------
ENTITY DigitalCertificate {
    definition:
        "A digitally signed electronic credential that binds an identity or
         named entity to a public key and associated attributes so that other
         entities can evaluate the authenticity and trust of that binding.";

    objectives: [
        IdentityBinding,
        PublicKeyDistribution,
        AuthenticationSupport,
        TrustEstablishment
    ];
}

# ---------- CORE ENTITIES ----------
CertificateSubject := {
    Person,
    Organisation,
    DomainName,
    Service,
    Device,
    Application
};

CertificateIssuer := {
    CertificateAuthority,
    IntermediateCertificateAuthority,
    TrustAnchor
};

CertificateData := {
    SubjectIdentity,
    IssuerIdentity,
    PublicKey,
    SerialNumber,
    ValidityPeriod,
    SignatureAlgorithm,
    DigitalSignature,
    Extensions
};

CertificateStatus := {
    Valid,
    Expired,
    Revoked,
    Suspended,
    Unknown,
    Invalid
};

# ---------- FUNDAMENTAL RELATIONSHIPS ----------
DigitalCertificate BINDS CertificateSubject TO PublicKey;
CertificateAuthority ISSUES DigitalCertificate;
CertificateAuthority SIGNS DigitalCertificate;
DigitalCertificate CONTAINS CertificateData;
DigitalCertificate HAS CertificateStatus;
DigitalCertificate HAS ValidityPeriod;
DigitalCertificate SUPPORTS Authentication;
DigitalCertificate PARTICIPATES_IN PublicKeyInfrastructure;

PublicKey CORRESPONDS_TO PrivateKey;
PrivateKey CONTROLLED_BY CertificateSubject;

# ---------- CERTIFICATE STRUCTURE ----------
DigitalCertificate :=
    {
        Version,
        SerialNumber,
        SignatureAlgorithm,
        Issuer,
        Validity,
        Subject,
        SubjectPublicKeyInfo,
        Extensions,
        CertificateSignature
    };

Validity :=
    (NotBefore, NotAfter);

IF CurrentTime < NotBefore
THEN CertificateStatus := Invalid;

IF CurrentTime > NotAfter
THEN CertificateStatus := Expired;

# ---------- ISSUANCE FLOW ----------
Subject ->
    GenerateKeyPair ->
    CreateCertificateRequest ->
    SubmitRequest ->
    ValidateIdentity ->
    ApproveRequest ->
    IssueCertificate ->
    SignCertificate ->
    DeliverCertificate;

KeyPair := {
    PublicKey,
    PrivateKey
};

CertificateRequest CONTAINS PublicKey;
CertificateRequest IDENTIFIES Subject;
Issuer VALIDATES SubjectBeforeIssuance;

# ---------- CERTIFICATE AUTHORITY ----------
CertificateAuthority :=
    TrustedIssuer;

CertificateAuthority HAS {
    SigningKey,
    CertificatePolicy,
    ValidationProcess,
    IssuanceProcess,
    RevocationProcess
};

CertificateAuthority USES PrivateSigningKey TO_SIGN DigitalCertificate;

RelyingParty USES IssuerPublicKey TO_VERIFY CertificateSignature;

# ---------- CERTIFICATE CHAIN ----------
CertificateChain :=
    EndEntityCertificate
    -> IntermediateCertificate*
    -> RootCertificate;

EndEntityCertificate ISSUED_BY IntermediateOrRootCA;
IntermediateCertificate ISSUED_BY HigherCA;
RootCertificate IS_A TrustAnchor;

ChainValidation ->
    VerifySignatures ->
    VerifyValidityPeriods ->
    VerifyConstraints ->
    VerifyTrustAnchor ->
    DetermineTrust;

# ---------- TRUST MODEL ----------
TrustAnchor := PretrustedCertificateOrPublicKey;

CertificateTrust :=
    f(
        ValidSignature,
        ValidChain,
        ValidityPeriod,
        CertificateStatus,
        PolicyCompliance,
        TrustedRoot
    );

IF ChainTerminatesAt TrustedRoot
AND AllValidationChecksPass
THEN CertificateTrust := Established;

# ---------- SIGNATURE VALIDATION ----------
CertificateSignature :=
    Sign(CertificateData, IssuerPrivateKey);

Verify(
    CertificateData,
    CertificateSignature,
    IssuerPublicKey
) -> Valid | Invalid;

IF CertificateSignature == Invalid
THEN CertificateStatus := Invalid;

# ---------- REVOCATION ----------
Revocation :=
    InvalidateCertificateBeforeExpiry;

RevocationReason MAY_INCLUDE {
    KeyCompromise,
    CACompromise,
    AffiliationChanged,
    Superseded,
    CessationOfOperation
};

RevocationInformation MAY_BE_PUBLISHED_BY {
    CertificateRevocationList,
    OnlineStatusProtocol
};

IF Certificate REVOKED
THEN CertificateStatus := Revoked;

IF CertificateStatus == Revoked
THEN CertificateTrust := Reject;

# ---------- CERTIFICATE EXTENSIONS ----------
CertificateExtension := {
    BasicConstraints,
    KeyUsage,
    ExtendedKeyUsage,
    SubjectAlternativeName,
    AuthorityKeyIdentifier,
    SubjectKeyIdentifier
};

KeyUsage RESTRICTS PermittedCryptographicUse;
ExtendedKeyUsage REFINES PermittedPurpose;
BasicConstraints MAY_IDENTIFY CertificateAuthorityCapability;
SubjectAlternativeName ASSOCIATES AdditionalIdentity;

# ---------- DOMAIN AND SERVICE IDENTITY ----------
ServiceCertificate BINDS ServiceIdentity TO PublicKey;

DomainCertificate MAY_IDENTIFY {
    DomainName,
    Subdomain,
    Hostname
};

IF RequestedIdentity MATCHES CertificateIdentity
THEN IdentityMatch := true;

IF RequestedIdentity DOES_NOT_MATCH CertificateIdentity
THEN IdentityValidation := fail;

# ---------- AUTHENTICATION RELATIONSHIP ----------
CertificateAuthentication ->
    PresentCertificate ->
    ValidateCertificate ->
    VerifyPrivateKeyPossession ->
    EstablishIdentityConfidence;

CertificateValidation ALONE DOES_NOT_PROVE PrivateKeyPossession;

IF CertificateValid
AND PrivateKeyPossessionVerified
THEN AuthenticationEvidence := Stronger;

# ---------- PUBLIC KEY INFRASTRUCTURE ----------
PKI := {
    CertificateAuthority,
    RegistrationFunction,
    DigitalCertificate,
    CertificateRepository,
    RevocationService,
    TrustAnchor,
    Policy
};

PKI MANAGES CertificateLifecycle;

CertificateLifecycle :=
    Request ->
    Validate ->
    Issue ->
    Deploy ->
    Use ->
    Renew ->
    RevokeOrExpire ->
    Replace;

# ---------- SECURITY THREATS ----------
CertificateThreat := {
    PrivateKeyCompromise,
    FraudulentIssuance,
    ExpiredCertificateUse,
    RevokedCertificateUse,
    InvalidChain,
    IdentityMismatch,
    WeakSignatureAlgorithm,
    CompromisedCertificateAuthority
};

CertificateThreat TARGETS {
    Certificate,
    KeyPair,
    CertificateAuthority,
    TrustChain,
    RelyingParty
};

SecurityControl MITIGATES CertificateThreat;

# ---------- SEMANTIC REASONING ----------
IF CertificateSignature VALID
AND CertificateWithinValidityPeriod
AND CertificateNotRevoked
AND CertificateChainValid
AND IdentityMatches
THEN CertificateValidation := Valid;

IF PrivateKey COMPROMISED
THEN AssociatedCertificate SHOULD_BE Revoked;

IF Certificate EXPIRED
THEN CertificateTrust := Reject;

IF Certificate REVOKED
THEN CertificateTrust := Reject;

IF Issuer NOT_TRUSTED
THEN CertificateTrust := NotEstablished;

IF RootCertificate TRUSTED
AND ChainValid
THEN ChainTrust := Established;

IF CertificateKeyUsage EXCLUDES RequestedUse
THEN RequestedCryptographicUse := Deny;

# ---------- SEMANTIC EQUIVALENCE ----------
SEMANTIC_EQUIVALENCE {
    "digital certificate" ~= "public key certificate";
    "certificate authority" ~= "CA";
    "certification authority" ~= "certificate authority";
    "certificate chain" ~= "certification path";
    "root certificate" ~= "trust anchor certificate" WHEN context == PKI;
    "certificate revocation list" ~= "CRL";
    "public key infrastructure" ~= "PKI";
    "certificate request" ~= "certificate signing request" WHEN context == issuance;
}

# ---------- QUERY FLOW ----------
QUERY(q) ->
    NORMALISE(q) ->
    IDENTIFY_CERTIFICATE_ENTITY(q) ->
    IDENTIFY_SUBJECT(q) ->
    IDENTIFY_ISSUER(q) ->
    IDENTIFY_KEY_RELATIONSHIP(q) ->
    IDENTIFY_CERTIFICATE_STATUS(q) ->
    MAP_TO_ONTOLOGY(q) ->
    APPLY_REASONING(q) ->
    SCORE_CONFIDENCE(q) ->
    RETURN_RELEVANT_KNOWLEDGE;

# ---------- CONFIDENCE ----------
CONFIDENCE(assertion) :=
    weighted_mean(
        source_reliability,
        cryptographic_consistency,
        trust_chain_consistency,
        semantic_consistency,
        contextual_relevance
    );

CONFIDENCE >= 0.90 => HIGH;
CONFIDENCE >= 0.70 AND < 0.90 => MODERATE;
CONFIDENCE < 0.70 => REVIEW;

# ---------- AI CONSUMPTION ----------
AI_CONSUMPTION {
    primary_entity: DigitalCertificate;
    ontology: DigitalCertificateOntology;
    parse_entities: true;
    parse_relationships: true;
    preserve_relationship_direction: true;
    resolve_semantic_equivalence: true;
    execute_reasoning_rules: true;
    apply_confidence_weighting: true;
    preserve_provenance: true;
}

# ---------- UPDATE MODEL ----------
UPDATE_MODEL {
    new_certificate_type:
        validate
        -> classify
        -> identify_subject
        -> identify_key_usage
        -> integrate;

    new_issuer:
        validate
        -> classify
        -> identify_trust_relationships
        -> integrate;

    status_change:
        identify_certificate
        -> update_status
        -> recompute_trust
        -> propagate_chain_effects
        -> integrate;

    policy_revision:
        update_validation_rules
        -> update_algorithm_requirements
        -> recompute_certificate_trust
        -> regenerate_flow_hash;

    conflict:
        preserve_provenance
        -> compare_evidence
        -> adjust_confidence
        -> flag_review;
}

# ---------- FLOW HASH ----------
FLOW_HASH_INPUT :=
    DOMAIN
    + SUBDOMAIN
    + ONTOLOGY
    + CertificateSubject
    + CertificateIssuer
    + CertificateData
    + CertificateStatus
    + CertificateChain
    + PKI
    + RELATIONSHIPS
    + SEMANTIC_REASONING
    + SEMANTIC_EQUIVALENCE
    + UPDATE_MODEL;

FLOW_HASH :=
    HASH(FLOW_HASH_INPUT);

# ---------- TERMINAL ----------
DigitalCertificateOntology
    -> IdentifySubject
    -> GenerateKeyPair
    -> ValidateIdentity
    -> IssueCertificate
    -> BindIdentityToPublicKey
    -> EstablishCertificateChain
    -> ValidateSignature
    -> ValidateStatus
    -> ValidateIdentityMatch
    -> EstablishCertificateTrust
    -> SupportSecureAuthentication;

END FLOW