Blockchain Addendum

Last updated: February 10, 2026

0. How Blockchain Features Relate to H33-74 Evidence

This section is explanatory context for the terms below; the operative provisions begin at Section 1. A Blockchain Feature under this Addendum is a mechanism for anchoring evidence to a third-party blockchain. The evidence itself — the portable 74-byte post-quantum attestation — is produced and anchored by H33-74, not by any Blockchain Network. A Blockchain Network provides only an anchor and a timestamp: it is a reference environment that evidence anchors to, and it is operated by third parties and not controlled by H33 (see Section 1.2). The chain does not produce the evidence, does not own it, and does not render any verdict about its validity.

Why this distinction matters for Customer. Because the H33-74 evidence is chain-agnostic — the same 32-byte commitment can be anchored to more than one network and re-verified against each — Customer's evidence does not depend on the survival of any single Blockchain Network. If H33 migrates Blockchain Features to a different network (Section 6), previously anchored records may remain on the original network, and the underlying evidence remains independently verifiable against its published schema and hash without trusting any chain. Whether a given attestation is valid is a matter for verification, not for the chain that stores its anchor.

By way of explanatory context only, and without limiting or modifying any operative provision below: a Customer typically uses a Blockchain Feature when it wants a public, third-party-witnessed timestamp or ordering anchored alongside its H33-74 evidence; where such a public anchor is not required, the underlying evidence remains independently verifiable without any Blockchain Network, and enabling a Blockchain Feature is optional.

1. Scope; Network; Definitions

1.1 Blockchain Features

Blockchain features may include recording authentication events, audit logs, compliance attestations, credential issuance (including soulbound NFTs), or other blockchain-linked functions (collectively, "Blockchain Features").

1.1(a) Token Features Cross-Reference

If Customer enables tokenized identity, credential issuance, document permissioning/access control, or Smart Contract functionality beyond blockchain logging/attestation, the Token Addendum applies in addition to this Blockchain Addendum.

1.2 Networks

Blockchain Features may use the Solana network and/or other third-party blockchain networks selected by H33 from time to time ("Blockchain Network"). Blockchain Networks are operated by third parties and are not controlled by H33.

1.3 Wallets

Customer is solely responsible for any digital wallet(s), private keys, custody solution, and access controls used in connection with Blockchain Features ("Wallet").

1.4 No Custody; No Key Management

H33 does not provide wallet custody, key recovery, escrow, fiduciary services, or financial institution services. Customer is solely responsible for Wallet selection, private key management, and access controls.

2. Customer Responsibilities and Restrictions

2.1 Configuration and Use

Customer is responsible for enabling Blockchain Features and configuring its integration. Customer must ensure any identifiers, payloads, or references Customer submits for blockchain writing are lawful and do not violate third-party rights.

2.2 No Sensitive Data On-Chain; Customer Controls Payload

Customer will not submit, write, or cause to be written to any Blockchain Network (including via identifiers, hashes, pointers, metadata, token metadata, permission tokens, access-control tokens, embedded references, or similar mechanisms):

• Plaintext biometric data
• Any "special category"/sensitive personal data
• PHI
• Payment card data
• Government identifiers
• Any data that Customer is not legally permitted to disclose or that would create an obligation to delete, correct, or provide access that cannot reasonably be satisfied on a Blockchain Network

Customer is solely responsible for the content and legality of any on-chain payloads and for ensuring all data written is appropriate for an immutable medium. Customer acknowledges that blockchain entries may be public, persistent, and not practically deletable.

2.3 End User Disclosures

Customer is solely responsible for providing any end user notices and obtaining any consents required for blockchain recording, credential issuance, or immutable logging.

2.4 Prohibited Use

Customer must not use Blockchain Features to circumvent law, engage in sanctions evasion, facilitate money laundering, or support illegal activity.

2.5 No Reliance; Not a System of Record

Blockchain Features are provided for optional attestation and logging convenience and are not intended to be a system of record for Customer's legal, regulatory, or audit obligations. Customer is solely responsible for independently maintaining records required by law, regulation, or contract and for determining whether Blockchain Features are suitable for Customer's use case.

2.6 Sanctions and Export Controls

Customer will not use Blockchain Features in violation of applicable sanctions or export control laws and will not use Blockchain Features for sanctions evasion. H33 may block or suspend Blockchain Features to comply with law or risk controls.

3. Irreversibility; No Deletion; No Rectification

3.1 Irreversible Transactions

Blockchain transactions are typically irreversible. Once data is written to a Blockchain Network, it may not be modifiable or deletable.

3.2 No Guaranteed Deletion

H33 cannot guarantee deletion, rectification, or removal of on-chain records, even if Customer requests it.

3.3 Customer Data on Chain

Any payload, identifier, reference, or instruction Customer causes to be written on a Blockchain Network is Customer Data. H33 is not responsible for public dissemination, third-party access, or downstream use of such on-chain data by Blockchain Network participants or third parties.

4. Fees; Network Conditions; Third-Party Terms

4.1 Network Fees and Pass-Through Costs

Customer is responsible for all Blockchain Network fees and third-party costs incurred in connection with Blockchain Features (including gas/transaction fees and any required priority fees), whether paid directly by Customer or advanced by H33. If H33 advances such fees, Customer authorizes H33 to charge Customer's payment method for the pass-through amounts (plus applicable taxes) in accordance with the Billing & Credits Policy.

4.2 Network Performance

Blockchain Networks may experience congestion, outages, forks, protocol changes, validator failures, or other issues. H33 is not responsible for Blockchain Network performance or availability.

4.3 Third-Party Terms

Customer's use of Blockchain Networks and Wallet providers may be subject to third-party terms. H33 is not responsible for third-party services.

4.4 Service Protection Controls

H33 may suspend, throttle, rate-limit, disable, or modify Blockchain Features at any time to protect the Services, manage cost exposure, comply with law, respond to security risk, or prevent abuse. H33 has no liability for any resulting unavailability or loss of access to Blockchain Features.

5. Credentials and SBTs (If Enabled)

5.1 Credential Issuance

If enabled, H33 may issue non-transferable credentials (including "soulbound" NFTs) as part of the Services.

5.2 No Guarantee of Recognition

H33 does not guarantee that any credential will be recognized, accepted, or portable across platforms or ecosystems.

5.3 Loss of Wallet Access

Loss of private keys or wallet access may be permanent. H33 cannot recover lost keys or restore access.

6. Migration; Changes

H33 may modify, upgrade, replace, or migrate Blockchain Features (including migrating to a different Blockchain Network) at any time. On-chain records created prior to migration may remain on the original network.

7. Disclaimers

8. Indemnity (Blockchain-Specific)

Customer will defend and indemnify H33 from and against claims arising from:

• Customer's on-chain submissions or instructions
• Customer's failure to provide required notices/consents
• Customer's Wallet management or security
• Customer's violation of law in connection with Blockchain Features
• Any allegation that Customer's on-chain submissions violated privacy, consumer protection, advertising, or data protection laws, or created an obligation to delete/correct/access data that cannot be practically satisfied

9. No Expansion of Liability

This Blockchain Addendum does not expand H33's liability or Customer remedies beyond the Terms, and the Terms' limitations of liability apply.

10. Frequently Asked Questions

This FAQ is explanatory and does not modify the operative terms above.