Warranty Contract

Overview

The Warranty contract (identipay::warranty) implements on-chain warranties as NFTs that are minted atomically with receipts during settlement. Warranties are:

Linked to receipts: Each warranty references its associated receipt
Encrypted: Warranty terms are AES-256-GCM ciphertext
Expirable: Plaintext expiry timestamp for on-chain enforcement
Optionally transferable: Can be marked transferable for resale scenarios

Source Code

Location: contracts/sources/warranty.move:6

Data Structures

WarrantyObject

On-chain warranty NFT minted during atomic settlement.

UID

required

Sui object identifier (unique warranty ID)

receipt_id

required

Reference to the associated receipt object

merchant

address

required

Merchant who issued the warranty

intent_hash

vector<u8>

required

Intent hash binding this warranty to a specific transaction

encrypted_terms

vector<u8>

required

AES-256-GCM ciphertext of warranty terms (duration, exclusions, service endpoints)

terms_nonce

vector<u8>

required

12-byte GCM nonce for terms decryption

ephemeral_pubkey

vector<u8>

required

Ephemeral public key E = e*G (same as receipt, for ECDH decryption)

expiry

u64

required

Warranty expiry timestamp in epoch milliseconds (plaintext for on-chain enforcement)

transferable

bool

required

Whether this warranty can be transferred (e.g., on resale)

public struct WarrantyObject has key, store {
    id: UID,
    receipt_id: ID,
    merchant: address,
    intent_hash: vector<u8>,
    encrypted_terms: vector<u8>,
    terms_nonce: vector<u8>,
    ephemeral_pubkey: vector<u8>,
    expiry: u64,
    transferable: bool,
}

Events

WarrantyMinted

Emitted when a warranty is minted.

warranty_id

Unique object ID of the warranty

receipt_id

Associated receipt ID

merchant

address

Merchant who issued the warranty

intent_hash

vector<u8>

Intent hash

expiry

u64

Warranty expiration timestamp

transferable

bool

Whether warranty is transferable

WarrantyTransferred

Emitted when a warranty is transferred.

warranty_id

Warranty object ID

from

address

Previous owner

address

New owner

Public Functions

mint_warranty

Mint a new warranty. Called by the settlement module during atomic execution. Function Signature:

public(package) fun mint_warranty(
    receipt_id: ID,
    merchant: address,
    intent_hash: vector<u8>,
    encrypted_terms: vector<u8>,
    terms_nonce: vector<u8>,
    ephemeral_pubkey: vector<u8>,
    expiry: u64,
    transferable: bool,
    ctx: &mut TxContext,
): WarrantyObject

receipt_id

required

Object ID of the associated receipt

merchant

address

required

Merchant’s Sui address

intent_hash

vector<u8>

required

Intent hash

encrypted_terms

vector<u8>

required

AES-256-GCM ciphertext of warranty terms

terms_nonce

vector<u8>

required

12-byte GCM nonce (must be exactly 12 bytes)

ephemeral_pubkey

vector<u8>

required

Ephemeral X25519 public key (must be exactly 32 bytes)

expiry

u64

required

Warranty expiration timestamp (epoch ms, must be > 0)

transferable

bool

required

Whether the warranty can be transferred

warranty

WarrantyObject

The minted warranty object

Errors:

EInvalidNonceLength (2): Nonce is not 12 bytes
EInvalidEphemeralPubkey (3): Ephemeral pubkey is not 32 bytes
EEmptyTerms (4): Encrypted terms are empty
EInvalidExpiry (5): Expiry is 0

Visibility: public(package) — only callable by the settlement module. Location: warranty.move:65-103

transfer_warranty

Transfer a warranty to a new address. Only allowed if the warranty is marked as transferable and has not expired. Function Signature:

public fun transfer_warranty(
    warranty: WarrantyObject,
    recipient: address,
    ctx: &TxContext,
)

warranty

WarrantyObject

required

Warranty object to transfer (consumed by this function)

recipient

address

required

New owner’s address

Errors:

EWarrantyNotTransferable (0): Warranty has transferable = false
EWarrantyExpired (1): Current time exceeds warranty expiry

Location: warranty.move:107-122 Example:

import { TransactionBlock } from '@mysten/sui.js/transactions';

// User wants to transfer warranty when selling an item
const tx = new TransactionBlock();

tx.moveCall({
  target: `${PACKAGE_ID}::warranty::transfer_warranty`,
  arguments: [
    tx.object(warrantyObjectId),
    tx.pure(newOwnerAddress),
  ],
});

await wallet.signAndExecuteTransactionBlock({ transactionBlock: tx });

Accessors

receipt_id

public fun receipt_id(warranty: &WarrantyObject): ID

Returns the associated receipt ID.

merchant

public fun merchant(warranty: &WarrantyObject): address

Returns the merchant’s address.

expiry

public fun expiry(warranty: &WarrantyObject): u64

Returns the expiry timestamp.

is_transferable

public fun is_transferable(warranty: &WarrantyObject): bool

Returns whether the warranty is transferable.

is_expired

public fun is_expired(warranty: &WarrantyObject, ctx: &TxContext): bool

Returns whether the warranty has expired. Location: warranty.move:149-155

Warranty Terms Format

The encrypted terms are a JSON object:

{
  "version": "1.0",
  "warranty": {
    "type": "manufacturer",
    "duration": "90 days",
    "coverage": [
      "Manufacturing defects",
      "Material defects",
      "Workmanship issues"
    ],
    "exclusions": [
      "Water damage",
      "Accidental damage",
      "Normal wear and tear"
    ],
    "serviceProcess": {
      "claimEmail": "[email protected]",
      "claimPhone": "+1-800-WARRANTY",
      "claimPortal": "https://example.com/warranty/claim",
      "requiredDocuments": [
        "Original receipt",
        "Photos of defect",
        "Product serial number"
      ]
    },
    "merchant": {
      "name": "Example Electronics",
      "supportEmail": "[email protected]"
    }
  }
}

Usage Example

import { aesGcmDecrypt, hkdf } from '@identipay/crypto';
import { sha256 } from '@noble/hashes/sha256';

// Fetch warranty from chain
const warranty = await suiClient.getObject({
  id: warrantyId,
  options: { showContent: true },
});

const {
  encrypted_terms,
  terms_nonce,
  ephemeral_pubkey,
  expiry,
  transferable,
} = warranty.data.content.fields;

// Check if expired
if (expiry <= Date.now()) {
  console.log('Warranty has expired');
  return;
}

// Derive shared secret (same as receipt decryption)
const sharedSecret = deriveECDH(
  stealthPrivateKey,
  merchantPublicKeyFromRegistry
);

// Derive AES key
const aesKey = hkdf(
  sha256,
  sharedSecret,
  'identipay-warranty',
  '',
  32
);

// Decrypt terms
const ciphertext = encrypted_terms.slice(0, -16);
const tag = encrypted_terms.slice(-16);

const plaintext = aesGcmDecrypt(
  aesKey,
  terms_nonce,
  ciphertext,
  tag
);

const warrantyTerms = JSON.parse(plaintext);
console.log('Warranty coverage:', warrantyTerms.warranty.coverage);
console.log('How to claim:', warrantyTerms.warranty.serviceProcess);

Transferability Scenarios

Non-Transferable Warranties (Soulbound)

For services or items that shouldn’t be resold:

// Merchant issues non-transferable warranty
await executeSettlement({
  // ...
  warranty_transferable: false,
});

// Later, if user tries to transfer:
try {
  await transferWarranty(warranty, newOwner);
} catch (e) {
  // Fails with EWarrantyNotTransferable
  console.error('This warranty cannot be transferred');
}

Use cases:

Software licenses (personal, non-transferable)
Service warranties tied to original purchaser
Medical products with liability concerns

Transferable Warranties

For physical goods that may be resold:

// Merchant issues transferable warranty
await executeSettlement({
  // ...
  warranty_transferable: true,
});

// User can transfer when selling the item
await transferWarranty(warranty, newOwnerAddress);

Use cases:

Electronics (phones, laptops)
Appliances (refrigerators, washing machines)
Vehicles
Collectibles with authenticity guarantees

Warranty Claims

Warranty claims happen off-chain using the decrypted terms:

Buyer Decrypts

Buyer decrypts warranty terms to find claim process (email, portal, phone).

Submit Claim

Buyer submits claim via merchant’s service portal with receipt proof.

Merchant Verifies

Merchant verifies:

Warranty has not expired (check expiry on-chain)
Receipt is authentic (check receipt_id matches on-chain)
Claim falls under coverage (check decrypted terms)

Resolution

Merchant processes claim (repair, replacement, refund) per terms.

Privacy Guarantees

Terms Privacy

Warranty terms (coverage, exclusions, process) are encrypted on-chain. Only buyer and merchant can decrypt.

Expiry Transparency

Expiry is plaintext for on-chain enforcement. This prevents expired warranties from being transferred.

Transferability Transparency

Transferability flag is plaintext so buyers know if they can resell the item with warranty.

Buyer Anonymity

Warranty is owned by a stealth address. On-chain observers cannot link it to buyer identity.

Security Considerations

Expiry Enforcement: The transfer_warranty function checks expiry on-chain. Expired warranties cannot be transferred, preventing fraud.

Receipt Linkage: Each warranty references its receipt via receipt_id. This enables verification that the warranty is authentic and corresponds to a real purchase.

Merchant Decryption: Merchants can decrypt all warranties they issued (for claim processing). This is necessary for warranty fulfillment.

Transfer Events: Warranty transfers emit events. Merchants can track transfers to update their claim databases.

Settlement

Mints warranties during atomic settlement

Receipt

Associated receipt linked via receipt_id

Trust Registry

Provides merchant public key for encryption

Smart Contracts

ZK Circuits

Cryptography

Overview

Source Code

Data Structures

WarrantyObject

Events

WarrantyMinted

WarrantyTransferred

Public Functions

mint_warranty

transfer_warranty

Accessors

receipt_id

merchant

expiry

is_transferable

is_expired

Warranty Terms Format

Usage Example

Transferability Scenarios

Non-Transferable Warranties (Soulbound)

Transferable Warranties

Warranty Claims

Privacy Guarantees

Security Considerations

Settlement

Receipt

Trust Registry

Build docs developers (and LLMs) love

Smart Contracts

ZK Circuits

Cryptography

​Overview

​Source Code

​Data Structures

​WarrantyObject

​Events

​WarrantyMinted

​WarrantyTransferred

​Public Functions

​mint_warranty

​transfer_warranty

​Accessors

​receipt_id

​merchant

​expiry

​is_transferable

​is_expired

​Warranty Terms Format

​Usage Example

​Transferability Scenarios

​Non-Transferable Warranties (Soulbound)

​Transferable Warranties

​Warranty Claims

​Privacy Guarantees

​Security Considerations

​Related Modules

Settlement

Receipt

Trust Registry

Build docs developers (and LLMs) love

Overview

Source Code

Data Structures

WarrantyObject

Events

WarrantyMinted

WarrantyTransferred

Public Functions

mint_warranty

transfer_warranty

Accessors

receipt_id

merchant

expiry

is_transferable

is_expired

Warranty Terms Format

Usage Example

Transferability Scenarios

Non-Transferable Warranties (Soulbound)

Transferable Warranties

Warranty Claims

Privacy Guarantees

Security Considerations

Related Modules