Every Spark Operator receives the full Lightning invoice tied to the wallet identity

What the evidence shows

Technical and product details

1. Documented behavior

   When creating a Lightning invoice, the SDK sends the coordinator the payment hash, complete BOLT11 invoice string, affected user's Spark identity, threshold, and one encrypted preimage share for every Operator. 1

   Supporting material shown on this page

   wallet preimage-share requestPinned source code · github.com · checked 2026-07-14

   173      await sparkClient.store_preimage_share_v2({
   174        paymentHash,
   175        encryptedPreimageShares: encryptedShares,
   176        threshold,
   177        invoiceString,
   178        userIdentityPublicKey,
   179      });

2. Documented behavior

   The coordinator fans that original request to all Operators. Each Operator decrypts its own share and stores the full invoice string, payment hash, threshold, and user identity in its own database. 23

   Supporting material shown on this page

   all-Operator preimage-share fan-outPinned source code · github.com · checked 2026-07-14

   152// StorePreimageShareV2 stores preimage shares for all SOs via a single coordinator call.
   153// The coordinator decrypts and stores its own share, then fans out to other SOs via internal RPC.
   154func (h *LightningHandler) StorePreimageShareV2(ctx context.Context, req *pbspark.StorePreimageShareV2Request) (retErr error) {
   155	if req == nil {
   156		return sparkerrors.InvalidArgumentMissingField(fmt.Errorf("request is required"))

   stored invoice and wallet identityPinned source code · github.com · checked 2026-07-14

   52			Comment("The identity public key of the operator that owns this preimage share.").
   53			Annotations(entexample.Default("02112b5bc18676433c593f8b02127354b9db8de6070088c1646a3cd58a60b90be3")),
   54		field.String("invoice_string").
   55			NotEmpty().
   56			Immutable().
   57			Comment("The original Lightning invoice string associated with the payment.").
   58			Annotations(entexample.Default("lnbc150n1p500ftzpp5v5kf3whqmujlh4wceer2jdfz0w074vjfs92myzsr8vcuclj7msvssp57pfy9xhj7ma00tzwwptwxse4wtn7yqffyy85t6tnwtf282px8w3sxqyz5vqnp4q0p92sfan5vj2a4f8q3gsfsy8qp60maeuxz858c5x0hvt5u0p0h9jrzjqtqd37k2ya0pv8pqeyjs4lklcexjyw600g9qqp62r4j0ph8fcmlfwqqqqzfv7u6g85qqqqqqq

3. Documented behavior

   The outgoing Lightning preimage-swap protocol likewise wraps the public request verbatim for all Operators. That request carries the BOLT11 invoice, exact sats, fee, payment hash, direction, receiver identity, and Spark transfer package. 456

   Supporting material shown on this page

   all-Operator outgoing Lightning requestPinned source code · github.com · checked 2026-07-14

   544// InitiatePreimageSwapPrepareRequest is the Prepare payload for the
   545// CONSENSUS_OPERATION_TYPE_INITIATE_PREIMAGE_SWAP 2PC flow. It wraps the public
   546// InitiatePreimageSwapRequest verbatim. Every SO runs the full preimage-swap
   547// validation (ValidateGetPreimageRequest, ValidateTransferPackage,
   548// buildHTLCRefundMaps), persists the transfer + preimage_request +

   outgoing request fieldsPinned source code · github.com · checked 2026-07-14

   202    paymentHash,
   203    invoiceString,
   204    isInboundPayment,
   205    feeSats = 0,
   206    amountSatsToSend,
   207    startTransferRequest,
   208    idempotencyKey,

   BOLT 11 invoice fieldsPinned source code · github.com · checked 2026-07-14

   145* `p` (1): `data_length` 52. 256-bit SHA256 payment_hash. Preimage of this provides proof of payment.
   146* `s` (16): `data_length` 52. This 256-bit secret prevents forwarding nodes from probing the payment recipient.
   147* `d` (13): `data_length` variable. Short description of purpose of payment (UTF-8), e.g. '1 cup of coffee' or 'ナンセンス 1杯'
   148* `m` (27): `data_length` variable. Additional metadata to attach to the
   149  payment. Note that the size of this field is limited by the maximum hop payload size. Long metadata fields reduce the maximum route length.
   150* `n` (19): `data_length` 53. 33-byte public key of the payee node
   151* `h` (23): `data_length` 52. 256-bit description of purpose of payment (SHA256). This is used to commit to an associated description that is over 639 bytes, but the transport mechanism for the description in that case is transport specific and not defined here.

Scope control

What this does not establish

• Each Operator normally decrypts only its own preimage or key-tweak share; this does not prove that one Operator holds every secret share. An inbound Lightning invoice does not automatically reveal the original payer's real identity, and the sources do not establish Operator retention periods or staff access policy. 234

Sources and excerpts

Primary sources

The relevant details and available source-code excerpts appear alongside the claims above. This list preserves the complete original-source trail for independent verification.