Cryptographic Asset Inventory

Property	Value
Controls	SID-CRYPTO-01 through SID-CRYPTO-05
EUDI Requirements	GEN-7.3.2-02, GEN-7.5-02, GEN-7.5-03, WIN-8.4.4-02
ISO 27001	A.8.24 (Cryptography)

Purpose

This document provides a formal inventory of all cryptographic assets across the SIROS ID platform: keys, algorithms, protection levels, and lifecycle properties. It addresses the finding that individual cryptographic controls exist and are verified, but a consolidated asset classification with ECCG mapping was missing.

ECCG Classification

The EUDI Cooperation Group (ECCG) Security Requirements classify cryptographic assets by their sensitivity level and required protection. The table below maps each SIROS ID cryptographic asset to the appropriate ECCG category.

ECCG Category	Assets in Scope	Required Protection
Issuer signing keys	HSM-backed ECDSA/RSA keys (vc)	HSM (PKCS#11 or QSCD) per GEN-7.5-02
User authentication keys	WebAuthn credentials, PRF-derived keys	Hardware authenticator or platform authenticator per WUH-8.3.1-Sec-07
Wallet instance keys	Per-credential ES256 signing key pairs	Client-side encrypted keystore per WIN-8.4.1-Sec-01
Transport keys	TLS certificates, mTLS client certs	Filesystem with restricted permissions; PKI-managed
Session secrets	JWT signing keys, admin tokens	Configuration secrets; operator-managed rotation
Ephemeral keys	ECDH (VP encryption), nonces	In-memory only; auto-destroyed on TTL or use

Asset Inventory by Component

Credential Issuer / Verifier (vc)

Asset	Algorithm	Size	Protection	Lifecycle
Issuer signing key (HSM)	ECDSA / or RSA	256–384 bit EC	PKCS#11 HSM — key never leaves HSM boundary	HSM-managed; PIN-authenticated sessions
Issuer signing key (software fallback)	ECDSA / or RSA	Variable	PEM file on filesystem	Manually provisioned; no at-rest encryption
mDOC Document Signer key	ECDSA / or Ed25519	256–384 bit	Same as issuer key (HSM or file)	IACA PKI-managed
Ephemeral VP encryption key	ECDH	256 bit	In-memory TTL cache (10 min)	Generated per VP request; auto-evicted
Cryptographic nonces	crypto/rand	256 bit (32 bytes)	In-memory, ephemeral	Single-use per flow
mDOC session MAC key	HMAC (COSE MAC)	Session-derived	In-memory per session	Session lifetime
DIDComm encryption keys	ECDH-ES+A256KW / ECDH-1PU+A256KW	X25519, ,	In-memory, ephemeral	Per-message generation
DIDComm signing keys	EdDSA, ES256, ES384, ES512	Variable	Via configured signer	Per-message
Content encryption (DIDComm)	A256GCM, A256CBC-HS512, XC20P	256 bit	In-memory, ephemeral	Per-message

Wallet Backend (go-wallet-backend)

Asset	Algorithm	Size	Protection	Lifecycle
JWT signing secret	HMAC-SHA256 (HS256)	Configurable	Config file, env var, or file path	Operator-provisioned; manual rotation
Admin API bearer token	Opaque (constant-time compare)	256 bit (32 bytes)	Config, env, file, or auto-generated	Auto-generated at startup if absent; no rotation mechanism
TLS server certificate + key	PKI-provisioned	Per certificate	Filesystem paths (PEM)	External PKI lifecycle
MongoDB mTLS client cert	PKI-provisioned	Per certificate	Filesystem paths (PEM)	External PKI lifecycle
Wallet provider attestation key	Operator-provisioned	Per key	Filesystem paths (PEM)	External PKI lifecycle

Wallet Frontend (wallet-frontend)

Asset	Algorithm	Size	Protection	Lifecycle
Main encryption key	AES-256-GCM	256 bit	Wrapped with AES-KW; stored in encrypted container	Generated at wallet creation; persisted server-side
Password-derived wrapping key	PBKDF2-SHA256 (600K iterations) → AES-KW	256 bit	Derived on-demand; never stored	Derived per unlock; random salt in container
PRF-derived wrapping key	HKDF-SHA256 → AES-KW	256 bit	Derived from authenticator PRF output	Derived per unlock; random salt/info per credential
ECDH encapsulation key pair (V2)	ECDH → AES-KW	256 bit	Private key AES-GCM wrapped with main key	Generated at wallet creation; persisted in container
Credential signing key pairs	ECDSA (ES256)	256 bit	JWK in JWE-encrypted container	Generated per did:key; no rotation
VP/KB-JWT signing	ES256 (via credential key)	256 bit	Same as credential key	Per-presentation
JWE container encryption	AES-256-GCM (via main key)	256 bit	Main key hierarchy	Full container re-encrypted on each save

Biometric Identity Verification (facetec-api)

Asset	Algorithm	Size	Protection	Lifecycle
JWT signing secret	HMAC (shared secret)	Configurable	Config file or env var	Operator-provisioned; manual rotation
Legacy app key	Opaque (constant-time compare)	Variable	Config, env, or file path	Operator-provisioned
FaceTec device key	Opaque (SDK key)	Variable	Config, env, or file path	FaceTec-provisioned
Issuer API key	Opaque (bearer token)	Variable	Config, env, or file path	Operator-provisioned
TLS server + mTLS upstream certs	PKI-provisioned	Per certificate	Filesystem paths (PEM)	External PKI lifecycle

Trust Evaluation (go-trust)

Asset	Algorithm	Size	Protection	Lifecycle
X.509 chain verification	PKIX path validation	N/A	Verification-only — no private key material	N/A
JWK/x5c public key parsing	Various (per key)	N/A	Verification-only	N/A
LoTE JWS verification	JWS (configurable toggle)	N/A	Verification-only	N/A
DID Web VH signature verification	EdDSA (eddsa-jcs-2022)	N/A	Verification-only	N/A

info

go-trust holds no private key material. It only verifies signatures and certificate chains from trust registries.

Policy Authorization (go-spocp)

No cryptographic operations. Pure S-expression policy matching engine.

Supported Algorithm Suite

Purpose	Algorithms	Notes
Credential signing	ES256, ES384, ES512, EdDSA, RS256, RS384, RS512	ES256 recommended for EUDIW
Key agreement	ECDH , ECDH , X25519	X25519 for DIDComm
Key wrapping	AES-KW-256	RFC 3394
Content encryption	AES-256-GCM, A256CBC-HS512, XC20P	AES-256-GCM primary
Key derivation	PBKDF2-SHA256 (600K), HKDF-SHA256	OWASP-compliant iteration count
Digest	SHA-256, SHA-384, SHA-512	SHA-256 default for MSO/SD-JWT
Random	crypto/rand (Go), WebCrypto API (browser)	CSPRNG throughout
TLS	TLS 1.2+ (configurable min), TLS 1.3 option

Key Hierarchy (Wallet Frontend)

Risk Observations

Observation	Impact	Mitigation Path
HMAC JWT secrets in config/env (wallet-backend, facetec-api)	Secret exposure if config leaks	Operator: use file-based secrets with restricted permissions; consider vault integration
PKCS#11 PIN in YAML config	HSM PIN exposure	Operator: externalize to secrets manager
File-based issuer keys (software fallback)	Plaintext PEM at rest	Use HSM mode for production deployments per GEN-7.5-02
No automated rotation for JWT signing secrets	Compromise window	Operator: establish rotation SOP
No rotation for wallet credential signing keys	Long-lived key material	Acceptable for credential-bound keys; keys destroyed with wallet
Admin token auto-generated but not rotated	Static admin credential	Operator: configure explicit token with rotation schedule