Fix var names in silent payments example

docs/_examples/silent_payments.adoc

@@ -17,3 +17,8 @@ include::{sourcedir}/lib/contracts/silent_payments.rb[tags=silent-payment]
 <3> Generate a tweaked key using receiver's address and sender's input key
 <4> Generate a tweaked private key for receiver using the sender's input key
 <5> Spend the received payment using the receiver's tweaked key
+
+We have a jupyter notebook that walks through the above
+example. link:https://github.com/pool2win/bitcoin-dsl/blob/main/notebooks/silent-payments.ipynb[Silent Payments
+Jupyter Notebook]
+

lib/contracts/silent_payments.rb

@@ -17,8 +17,6 @@
 
 # frozen_string_literal: false
 
-node :reset
-
 # tag::silent-payment[]
 @sender_input_key = key :new # <1>
 @sender = key :new
@@ -28,9 +26,9 @@
 
 @sender_coinbase = spendable_coinbase_for @sender_input_key # <2>
 
-@sender_dh_key = multiply point: @receiver, scalar: @sender_input_key # <3>
+@sender_dh_share = multiply point: @receiver, scalar: @sender_input_key # <3>
 
-@taproot_output_key = tweak_public_key @receiver, with: hash160(@sender_dh_key) # <3>
+@taproot_output_key = tweak_public_key @receiver, with: hash160(@sender_dh_share) # <3>
 
 @taproot_output_tx = transaction inputs: [{ tx: @sender_coinbase,
                                             vout: 0,
@@ -56,5 +54,5 @@
 
 assert_mempool_accept @spend_received_payment_tx
 broadcast @spend_received_payment_tx
-confirm transaction @spend_received_payment_tx
+confirm transaction: @spend_received_payment_tx
 # end::silent-payment[]

notebooks/silent-payments.ipynb

@@ -20,19 +20,19 @@
    ]
   },
   {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "1ac612b0-1925-48af-93c9-397d3cbbd389",
+   "cell_type": "markdown",
+   "id": "1494f763-79c9-48f2-8015-3f279f4a98df",
    "metadata": {},
-   "outputs": [],
    "source": [
-    "node :reset"
+    "#### Create Keys\n",
+    "\n",
+    "The sender_input_key is the key from the input that the sender spends to create the silent payment."
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "82a6a946-c6f3-4291-bfaa-21dd3c2a6021",
+   "id": "ea04c5c6-f268-48da-84c9-5e13ed0900ab",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -42,87 +42,93 @@
    ]
   },
   {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "e715fc9d-cde5-4d61-bf9f-bb28dee1cb33",
+   "cell_type": "markdown",
+   "id": "f1f9c9ac-a4fd-4325-b04e-e83956ef5ea3",
    "metadata": {},
-   "outputs": [],
    "source": [
-    "extend_chain to: @sender_input_key, num_blocks: 101"
+    "#### Create Coinbases for Sender"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "b6df634b-f118-48e9-9e42-1b1c77d07d59",
+   "id": "d595ffb2-78d3-4e5a-b39e-273ab30fd2a8",
    "metadata": {},
    "outputs": [],
    "source": [
+    "extend_chain to: @sender_input_key, num_blocks: 101\n",
+    "\n",
     "@sender_coinbase = spendable_coinbase_for @sender_input_key"
    ]
   },
   {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "48bb6323-6efd-4eaf-bbbd-0db9e737074d",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "@sender_dh_key = multiply point: @receiver, scalar: @sender_input_key"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "e952ad11-56cd-451a-8f54-3888a506e594",
+   "cell_type": "markdown",
+   "id": "98e48fd7-8b3e-444f-ab42-ebefaa85f65d",
    "metadata": {},
-   "outputs": [],
    "source": [
-    "@taproot_output_key = tweak_public_key @receiver, with: hash160(@sender_dh_key)"
+    "#### Generate Silent Payment\n",
+    "\n",
+    "First we create the DH shared secret.\n",
+    "\n",
+    "We use that to tweak the receiver's public key to get the internal key to be used for the taproot transaction."
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "1b9fe805-9c8e-4e0e-a581-6c5297633bdf",
+   "id": "be0e5aa5-ec73-423c-a5d2-008652c5969e",
    "metadata": {},
    "outputs": [],
    "source": [
+    "@sender_dh_share = multiply point: @receiver, scalar: @sender_input_key\n",
+    "\n",
+    "@taproot_output_key = tweak_public_key @receiver, with: hash160(@sender_dh_share)\n",
+    "\n",
     "@taproot_output_tx = transaction inputs: [{ tx: @sender_coinbase, vout: 0, script_sig: 'sig:wpkh(@sender_input_key)' }],\n",
     "                                 outputs: [{ amount: 49.999.sats, taproot: { internal_key: @taproot_output_key } }]"
    ]
   },
   {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "13985d37-d286-439f-81f7-d597062d5b06",
+   "cell_type": "markdown",
+   "id": "c7eb1a9e-ebab-4a1d-b556-8e33bd954417",
    "metadata": {},
-   "outputs": [],
    "source": [
-    "broadcast @taproot_output_tx"
+    "#### Broadcast and Confirm the Silent Payment "
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "e489e724-e77e-496d-a874-7d59401408e4",
+   "id": "f2880a4e-51e3-4639-889c-58468412f302",
    "metadata": {},
    "outputs": [],
    "source": [
+    "broadcast @taproot_output_tx\n",
+    "\n",
     "confirm transaction: @taproot_output_tx\n",
     "extend_chain num_blocks: 100"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "68316f7d-27f1-4ed0-a0dd-936e764a3f11",
+   "id": "be0c2d8c-cc23-4b22-b2b3-7cc1e61d3682",
    "metadata": {},
    "outputs": [],
    "source": [
     "assert_equal @taproot_output_tx.inputs[0].script_witness.stack[1].bth, @sender_input_key.pubkey"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "3aaf7157-5bf9-4195-8585-0e2e4e122c44",
+   "metadata": {},
+   "source": [
+    "#### Tweak the Receiver's Private Key\n",
+    "\n",
+    "The receiver is watching the chain for a taproot transaction where the internal key is the receiver's public key tweaked with a DH secret. When a match is found, the receiver can spend that output whenever they want."
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,