Examples from Sighash and Partial Transaction Signing

All examples from the sighash documentation chapter are shown here in full. The specific examples referenced in the subsections are wrapped in the functions listed below.

Sighash ALL

• sign_verify_sighash_all();

Sighash NONE

• sign_sighash_none();

Sighash SINGLE

• sign_sighash_single();

Sighash ANYONECANPAY

• sign_none_anyonecanpay();

Libbitcoin API: Libbitcoin version 3. For upcoming version 4, the script::verify() method will have a simplified function signature.

Compile with: g++ -std=c++11 -o sign_verify_sighash sighash_examples.cpp $(pkg-config --cflags libbitcoin --libs libbitcoin)

#include <bitcoin/bitcoin.hpp>
#include <string.h>
#include <iostream>

using namespace bc;
using namespace wallet;
using namespace chain;
using namespace machine;


void sign_sighash_all() {
    // SETUP (Not shown in chapter documentation).
    // Private key, public keys.
    auto my_secret0 = base16_literal(
        "3eec08386d08321cd7143859e9bf4d6f65a71d24f37536d76b4224fdea48009f");
    auto my_secret1 = base16_literal(
        "86faa240ae2b0f28b125a42961bd3adf9d5f5dc6a1deaa5feda04e7be8c872f6");
    auto my_secret2 = base16_literal(
        "b7423c94ab99d3295c1af7e7bbea47c75d298f7190ca2077b53bae61299b70a5");
    auto my_secret3 = base16_literal(
        "d977e2ce0f744dc3432cde9813a99360a3f79f7c8035ef82310d54c57332b2cc");
    ec_private my_private0(my_secret0, ec_private::testnet, true); //compressed
    ec_private my_private1(my_secret1, ec_private::testnet, true); //compressed
    ec_private my_private2(my_secret2, ec_private::testnet, true); //compressed
    ec_private my_private3(my_secret3, ec_private::testnet, true); //compressed
    payment_address my_address0 = my_private0.to_payment_address();
    payment_address my_address1 = my_private1.to_payment_address();
    payment_address my_address2 = my_private2.to_payment_address();
    payment_address my_address3 = my_private3.to_payment_address();
    ec_compressed pubkey0 = my_private0.to_public().point();
    ec_compressed pubkey1 = my_private1.to_public().point();

    // Version.
    uint32_t version = 1u;
    transaction tx;
    tx.set_version(version);

    // Build input 0.
    std::string prev_tx_string_0 =
        "7ea970031b28fcc1cef517dfa7d812cb61c409aec37a0463e951a05700d61b73";
    hash_digest prev_tx_hash_0;
    decode_hash(prev_tx_hash_0,prev_tx_string_0);
    // Prev uxto index.
    uint32_t index0 = 0;
    output_point uxto_tospend_0(prev_tx_hash_0, index0);
    // Input object.
    input input_0;
    input_0.set_previous_output(uxto_tospend_0);
    input_0.set_sequence(max_input_sequence);
    // Build input 1.
    std::string prev_tx_string_1 =

        "32d070ed7d387b9db02bf35f3ba1c0ee61837c2226fd5cbf0c913525a9be869d";
    hash_digest prev_tx_hash_1;
    decode_hash(prev_tx_hash_1,prev_tx_string_1);
    // Prev uxto index.
    uint32_t index1 = 0;
    output_point uxto_tospend_1(prev_tx_hash_1, index1);
    // Input object.
    input input_1;
    input_1.set_previous_output(uxto_tospend_1);
    input_1.set_sequence(max_input_sequence);

    // Build output 0.
    operation::list locking_script_0 =
        script::to_pay_key_hash_pattern(my_address2.hash());
    std::string btc_amount_string_0 = "1";
    uint64_t satoshi_amount_0;
    decode_base10(satoshi_amount_0, btc_amount_string_0, btc_decimal_places);
    output output_0(satoshi_amount_0, locking_script_0);
    // Build output 1.
    operation::list locking_script_1 =
        script::to_pay_key_hash_pattern(my_address3.hash());
    std::string btc_amount_string_1 = "0.945";
    uint64_t satoshi_amount_1;
    decode_base10(satoshi_amount_1, btc_amount_string_1, btc_decimal_places);
    output output_1(satoshi_amount_1, locking_script_1);
    // Build locktime.


    //****************************************//
    // SIGHASH ALL chapter example begins here.

    // Not shown:
    // Construction of inputs and outputs.

    // Finalise TX - can't be modified later.
    tx.inputs().push_back(input_0);   //first input
    tx.inputs().push_back(input_1);   //second input
                                      //...nth input
    tx.outputs().push_back(output_0); //first output
    tx.outputs().push_back(output_1); //second output
                                      //...nth output

    // Construct previous output script of input_0 & input_1.
    script prevout_script0 = script::to_pay_key_hash_pattern(my_address0.hash());
    script prevout_script1 = script::to_pay_key_hash_pattern(my_address1.hash());

    // TX signature for input_0.
    endorsement sig_0;
    uint8_t input0_index(0u);
    script::create_endorsement(sig_0, my_secret0, prevout_script0, tx,
        input0_index, sighash_algorithm::all);

    // TX signature for input_1.
    endorsement sig_1;
    uint8_t input1_index(1u);
    script::create_endorsement(sig_1, my_secret1, prevout_script1, tx,
        input1_index, sighash_algorithm::all);

    // Construct input script_0.
    operation::list sig_script_0;
    sig_script_0.push_back(operation(sig_0));
    sig_script_0.push_back(operation(to_chunk(pubkey0)));
    script input_script0(sig_script_0);

    // Construct input script_1.
    operation::list sig_script_1;
    sig_script_1.push_back(operation(sig_1));
    sig_script_1.push_back(operation(to_chunk(pubkey1)));
    script input_script1(sig_script_1);

    // Add unlockingscript to TX.
    tx.inputs()[input0_index].set_script(input_script0);
    tx.inputs()[input1_index].set_script(input_script1);

    // ALL: We cannot modify TX after signing.

    witness empty_witness;      // Only verified in a p2w tx.
    uint64_t prevout_amount(1); // Only verified in a p2w endorsement.

    // Verify input script (and endorsement) for input 0.
    auto ec_input0 = script::verify(tx, input0_index,rule_fork::all_rules,
          input_script0, empty_witness, prevout_script0,
          prevout_amount);
    // Success.
    std::cout << ec_input0.message() << std::endl;

    // Verify input script (and endorsement) for input 1.
    auto ec_input1 = script::verify(tx, input1_index,rule_fork::all_rules,
          input_script1, empty_witness, prevout_script1,
          prevout_amount);
    // Success.
    std::cout << ec_input1.message() << std::endl;

}

void sign_sighash_none() {
    // SETUP (IDENTICAL IN ALL EXAMPLES)
    // Private key, public keys.
    auto my_secret0 = base16_literal(
        "3eec08386d08321cd7143859e9bf4d6f65a71d24f37536d76b4224fdea48009f");
    auto my_secret1 = base16_literal(
        "86faa240ae2b0f28b125a42961bd3adf9d5f5dc6a1deaa5feda04e7be8c872f6");
    auto my_secret2 = base16_literal(
        "b7423c94ab99d3295c1af7e7bbea47c75d298f7190ca2077b53bae61299b70a5");
    auto my_secret3 = base16_literal(
        "d977e2ce0f744dc3432cde9813a99360a3f79f7c8035ef82310d54c57332b2cc");
    ec_private my_private0(my_secret0, ec_private::testnet, true); //compressed
    ec_private my_private1(my_secret1, ec_private::testnet, true); //compressed
    ec_private my_private2(my_secret2, ec_private::testnet, true); //compressed
    ec_private my_private3(my_secret3, ec_private::testnet, true); //compressed
    payment_address my_address0 = my_private0.to_payment_address();
    payment_address my_address1 = my_private1.to_payment_address();
    payment_address my_address2 = my_private2.to_payment_address();
    payment_address my_address3 = my_private3.to_payment_address();
    ec_compressed pubkey0 = my_private0.to_public().point();
    ec_compressed pubkey1 = my_private1.to_public().point();

    // Version.
    uint32_t version = 1u;
    transaction tx;
    tx.set_version(version);

    // Build input 0.
    std::string prev_tx_string_0 =
        "e964ed0883933ae8f3f53139efef149b0cedb7895a040cab3b64e792acd11412";
    hash_digest prev_tx_hash_0;
    decode_hash(prev_tx_hash_0,prev_tx_string_0);
    // Prev uxto index.
    uint32_t index0 = 0;
    output_point uxto_tospend_0(prev_tx_hash_0, index0);
    // Input object.
    input input_0;
    input_0.set_previous_output(uxto_tospend_0);
    input_0.set_sequence(max_input_sequence);
    // Build input 1.
    std::string prev_tx_string_1 =
        "0aea180c6a3b0233574e9e51f065cd1996f1db6f8a10c72fc480151be323d956";
    hash_digest prev_tx_hash_1;
    decode_hash(prev_tx_hash_1,prev_tx_string_1);
    // Prev uxto index.
    uint32_t index1 = 0;
    output_point uxto_tospend_1(prev_tx_hash_1, index1);
    // Input object.
    input input_1;
    input_1.set_previous_output(uxto_tospend_1);
    input_1.set_sequence(max_input_sequence);

    // Build output 0.
    operation::list locking_script_0 =
        script::to_pay_key_hash_pattern(my_address2.hash());
    std::string btc_amount_string_0 = "0.2";
    uint64_t satoshi_amount_0;
    decode_base10(satoshi_amount_0, btc_amount_string_0, btc_decimal_places);
    output output_0(satoshi_amount_0, locking_script_0);
    // Build output 1.
    operation::list locking_script_1 =
        script::to_pay_key_hash_pattern(my_address3.hash());
    std::string btc_amount_string_1 = "0.287";
    uint64_t satoshi_amount_1;
    decode_base10(satoshi_amount_1, btc_amount_string_1, btc_decimal_places);
    output output_1(satoshi_amount_1, locking_script_1);
    // Build locktime.


    //****************************************//
    // SIGHASH NONE chapter example begins here.

    // Not shown:
    // Construction of inputs and outputs.

    // We only need to finalise inputs. Outputs can be modified after signing.
    tx.inputs().push_back(input_0);   //first input
    tx.inputs().push_back(input_1);   //second input
                                      //...nth input

    // Construct previous output script of input_0 & input_1
    script prevout_script0 = script::to_pay_key_hash_pattern(my_address0.hash());
    script prevout_script1 = script::to_pay_key_hash_pattern(my_address1.hash());

    // TX signature for input_0.
    endorsement sig_0;
    uint8_t input0_index(0u);
    script::create_endorsement(sig_0, my_secret0, prevout_script0, tx,
        input0_index, sighash_algorithm::none);

    // TX signature for input_1.
    endorsement sig_1;
    uint8_t input1_index(1u);
    script::create_endorsement(sig_1, my_secret1, prevout_script1, tx,
        input1_index, sighash_algorithm::none);

    // Construct input script_0.
    operation::list sig_script_0;
    sig_script_0.push_back(operation(sig_0));
    sig_script_0.push_back(operation(to_chunk(pubkey0)));
    script input_script0(sig_script_0);

    // Construct input script_1.
    operation::list sig_script_1;
    sig_script_1.push_back(operation(sig_1));
    sig_script_1.push_back(operation(to_chunk(pubkey1)));
    script input_script1(sig_script_1);

    // Add unlockingscript to TX.
    tx.inputs()[input0_index].set_script(input_script0);
    tx.inputs()[input1_index].set_script(input_script1);

    // NONE: We can modify all outputs after signing
    tx.outputs().push_back(output_0); //first output
    tx.outputs().push_back(output_1); //second output
                                      //...nth output

    witness empty_witness;      // Only verified in a p2w tx.
    uint64_t prevout_amount(1); // Only verified in a p2w endorsement.

    // Verify input script (and endorsement) for input 0.
    auto ec_input0 = script::verify(tx, input0_index,rule_fork::all_rules,
          input_script0, empty_witness, prevout_script0,
          prevout_amount);

    // Success.
    std::cout << ec_input0.message() << std::endl;

    // Verify input script (and endorsement) for input 1.
    auto ec_input1 = script::verify(tx, input1_index,rule_fork::all_rules,
          input_script1, empty_witness, prevout_script1,
          prevout_amount);

    // Success.
    std::cout << ec_input1.message() << std::endl;

}

void sign_sighash_single() {
    // SETUP (IDENTICAL IN ALL EXAMPLES).
    // Private key, public keys.
    auto my_secret0 = base16_literal(
        "3eec08386d08321cd7143859e9bf4d6f65a71d24f37536d76b4224fdea48009f");
    auto my_secret1 = base16_literal(
        "86faa240ae2b0f28b125a42961bd3adf9d5f5dc6a1deaa5feda04e7be8c872f6");
    auto my_secret2 = base16_literal(
        "b7423c94ab99d3295c1af7e7bbea47c75d298f7190ca2077b53bae61299b70a5");
    auto my_secret3 = base16_literal(
        "d977e2ce0f744dc3432cde9813a99360a3f79f7c8035ef82310d54c57332b2cc");
    ec_private my_private0(my_secret0, ec_private::testnet, true); //compressed
    ec_private my_private1(my_secret1, ec_private::testnet, true); //compressed
    ec_private my_private2(my_secret2, ec_private::testnet, true); //compressed
    ec_private my_private3(my_secret3, ec_private::testnet, true); //compressed
    payment_address my_address0 = my_private0.to_payment_address();
    payment_address my_address1 = my_private1.to_payment_address();
    payment_address my_address2 = my_private2.to_payment_address();
    payment_address my_address3 = my_private3.to_payment_address();
    ec_compressed pubkey0 = my_private0.to_public().point();
    ec_compressed pubkey1 = my_private1.to_public().point();

    // Version.
    uint32_t version = 1u;
    transaction tx;
    tx.set_version(version);

    // Build input 0.
    std::string prev_tx_string_0 =
        "3af74abff61f5a8486da92a8fc5e31dc10b899862bf3468d0505a5c1ca550b52";
    hash_digest prev_tx_hash_0;
    decode_hash(prev_tx_hash_0,prev_tx_string_0);
    // Prev uxto index.
    uint32_t index0 = 0;
    output_point uxto_tospend_0(prev_tx_hash_0, index0);
    // Input object.
    input input_0;
    input_0.set_previous_output(uxto_tospend_0);
    input_0.set_sequence(max_input_sequence);
    // Build input 1.
    std::string prev_tx_string_1 =
        "de065530166c16ab1c820b2f4e8e70d8b4259de263d18e47efde41f30ec79970";
    hash_digest prev_tx_hash_1;
    decode_hash(prev_tx_hash_1,prev_tx_string_1);
    // Prevout index.
    uint32_t index1 = 0;
    output_point uxto_tospend_1(prev_tx_hash_1, index1);
    // Input object.
    input input_1;
    input_1.set_previous_output(uxto_tospend_1);
    input_1.set_sequence(max_input_sequence);

    // Build output 0.
    operation::list locking_script_0 =
        script::to_pay_key_hash_pattern(my_address2.hash());
    std::string btc_amount_string_0 = "0.041";
    uint64_t satoshi_amount_0;
    decode_base10(satoshi_amount_0, btc_amount_string_0, btc_decimal_places);
    output output_0(satoshi_amount_0, locking_script_0);
    // Build output 1.
    operation::list locking_script_1
        = script::to_pay_key_hash_pattern(my_address3.hash());
    std::string btc_amount_string_1 = "0.03";
    uint64_t satoshi_amount_1;
    decode_base10(satoshi_amount_1, btc_amount_string_1, btc_decimal_places);
    output output_1(satoshi_amount_1, locking_script_1);
    // Build output 2.
    operation::list locking_script_2
        = script::to_pay_key_hash_pattern(my_address3.hash());
    std::string btc_amount_string_2 = "0.03";
    uint64_t satoshi_amount_2;
    decode_base10(satoshi_amount_2, btc_amount_string_2, btc_decimal_places);
    output output_2(satoshi_amount_2, locking_script_2);


    //****************************************//
    // SIGHASH SINGLE chapter example begins here.

    // Not shown:
    // Construction of inputs and outputs.


    // We sign all inputs and single output with same index.
    tx.inputs().push_back(input_0);   //first input
    tx.outputs().push_back(output_0); //first output
    tx.inputs().push_back(input_1);   //second input
    tx.outputs().push_back(output_1); //second output
                                      //...nth input
                                      //...nth output

    // Construct previous output scripts of input_0 & input_1.
    script prevout_script0 = script::to_pay_key_hash_pattern(my_address0.hash());
    script prevout_script1 = script::to_pay_key_hash_pattern(my_address1.hash());

    // TX signature for input_0.
    endorsement sig_0;
    uint8_t input0_index(0u);
    script::create_endorsement(sig_0, my_secret0, prevout_script0, tx,
          input0_index, sighash_algorithm::single);

    // TX signature for input_1.
    endorsement sig_1;
    uint8_t input1_index(1u);
    script::create_endorsement(sig_1, my_secret1, prevout_script1, tx,
          input1_index, sighash_algorithm::single);

    // Construct input script_0.
    operation::list sig_script_0;
    sig_script_0.push_back(operation(sig_0));
    sig_script_0.push_back(operation(to_chunk(pubkey0)));
    script input_script0(sig_script_0);

    // Construct input script_1.
    operation::list sig_script_1;
    sig_script_1.push_back(operation(sig_1));
    sig_script_1.push_back(operation(to_chunk(pubkey1)));
    script input_script1(sig_script_1);

    // Add unlockingscript to TX.
    tx.inputs()[input0_index].set_script(input_script0);
    tx.inputs()[input1_index].set_script(input_script1);

    // SINGLE: We can add additional outputs after signing.
    tx.outputs().push_back(output_2); //third output
                                      //...nth output

    witness empty_witness;      // Only verified in a p2w tx.
    uint64_t prevout_amount(1); // Only verified in a p2w endorsement.

    // Verify input script (and endorsement) for input 0.
    auto ec_input0 = script::verify(tx, input0_index,rule_fork::all_rules,
          input_script0, empty_witness, prevout_script0,
          prevout_amount);

    // Success.
    std::cout << ec_input0.message() << std::endl;

    // Verify input script (and endorsement) for input 1.
    auto ec_input1 = script::verify(tx, input1_index,rule_fork::all_rules,
          input_script1, empty_witness, prevout_script1,
          prevout_amount);

    // Success.
    std::cout << ec_input1.message() << std::endl;

}


void sign_none_anyonecanpay() {

    // SETUP (IDENTICAL IN ALL EXAMPLES).
    // Private key, public keys.
    auto my_secret0 = base16_literal(
        "3eec08386d08321cd7143859e9bf4d6f65a71d24f37536d76b4224fdea48009f");
    auto my_secret1 = base16_literal(
        "86faa240ae2b0f28b125a42961bd3adf9d5f5dc6a1deaa5feda04e7be8c872f6");
    auto my_secret2 = base16_literal(
        "b7423c94ab99d3295c1af7e7bbea47c75d298f7190ca2077b53bae61299b70a5");
    auto my_secret3 = base16_literal(
        "d977e2ce0f744dc3432cde9813a99360a3f79f7c8035ef82310d54c57332b2cc");
    ec_private my_private0(my_secret0, ec_private::testnet, true); //compressed
    ec_private my_private1(my_secret1, ec_private::testnet, true); //compressed
    ec_private my_private2(my_secret2, ec_private::testnet, true); //compressed
    ec_private my_private3(my_secret3, ec_private::testnet, true); //compressed
    payment_address my_address0 = my_private0.to_payment_address();
    payment_address my_address1 = my_private1.to_payment_address();
    payment_address my_address2 = my_private2.to_payment_address();
    payment_address my_address3 = my_private3.to_payment_address();
    ec_compressed pubkey0 = my_private0.to_public().point();
    ec_compressed pubkey1 = my_private1.to_public().point();

    //Version.
    uint32_t version = 1u;
    transaction tx;
    tx.set_version(version);

    // Build input 0.
    std::string prev_tx_string_0 =
        "48828a16d0b93111272ec1721fceb29518efbd663c183e156873724ded5fe15d";
    hash_digest prev_tx_hash_0;
    decode_hash(prev_tx_hash_0,prev_tx_string_0);
    // Prevout index.
    uint32_t index0 = 0;
    output_point uxto_tospend_0(prev_tx_hash_0, index0);
    // Input object.
    input input_0;
    input_0.set_previous_output(uxto_tospend_0);
    input_0.set_sequence(max_input_sequence);
    // Build input 1.
    std::string prev_tx_string_1 =
        "e97db8ffd52711bbe012b7b1875e59106424dbfacd6938c688ca9535655c89ec";
    hash_digest prev_tx_hash_1;
    decode_hash(prev_tx_hash_1,prev_tx_string_1);
    // Prevout index.
    uint32_t index1 = 0;
    output_point uxto_tospend_1(prev_tx_hash_1, index1);
    // Input object.
    input input_1;
    input_1.set_previous_output(uxto_tospend_1);
    input_1.set_sequence(max_input_sequence);

    // Build output 0.
    operation::list locking_script_0 =
        script::to_pay_key_hash_pattern(my_address2.hash());
    std::string btc_amount_string_0 = "0.03";
    uint64_t satoshi_amount_0;
    decode_base10(satoshi_amount_0, btc_amount_string_0, btc_decimal_places);
    output output_0(satoshi_amount_0, locking_script_0);
    // Build output 1.
    operation::list locking_script_1 =
        script::to_pay_key_hash_pattern(my_address3.hash());
    std::string btc_amount_string_1 = "0.02";
    uint64_t satoshi_amount_1;
    decode_base10(satoshi_amount_1, btc_amount_string_1, btc_decimal_places);
    output output_1(satoshi_amount_1, locking_script_1);
    // Build locktime.

    //****************************************//
    // Specific setup for SIGHASH NONE|ANYONECANPAY example.
    // We prepare an endorsed input at index 1.

    // We create a TX copy for input_1 signing.
    transaction tx2 = tx;
    // Create previous script.
    script prevout_script1 = script::to_pay_key_hash_pattern(my_address1.hash());
    // Push input into TX2.
    input empty_input;
    tx2.inputs().push_back(empty_input); //A placeholder for input_0.
    tx2.inputs().push_back(input_1);
    // TX signature for input_1.
    endorsement sig_1;
    uint8_t input1_index(1u);
    script::create_endorsement(sig_1, my_secret1, prevout_script1, tx2,
        input1_index, none_anyone_can_pay);
    // Construct input script 1.
    operation::list sig_script_1;
    sig_script_1.push_back(operation(sig_1));
    sig_script_1.push_back(operation(to_chunk(pubkey1)));
    script input_script1(sig_script_1);
    input_1.set_script(input_script1);


    //****************************************//
    // SIGHASH NONE|ANYONECANPAY example.

    // Not shown:
    // Construction of inputs and outputs.

    // We only sign a single input.
    tx.inputs().push_back(input_0);

    // Construct previous output script of input_0.
    script prevout_script0 = script::to_pay_key_hash_pattern(my_address0.hash());

    // TX signature for input_0.
    endorsement sig_0;
    uint8_t input0_index(0u);
    script::create_endorsement(sig_0, my_secret0, prevout_script0, tx,
        input0_index, none_anyone_can_pay);

    // Construct input script_0.
    operation::list sig_script_0;
    sig_script_0.push_back(operation(sig_0));
    sig_script_0.push_back(operation(to_chunk(pubkey0)));
    script input_script0(sig_script_0);

    // Add unlockingscript to TX.
    tx.inputs()[input0_index].set_script(input_script0);

    // ANYONECANPAY: We can modify other inputs after signing.
    // Important: input added here must include valid input script!
    // ...and previously be signed with tx index = 1
    tx.inputs().push_back(input_1);   //second input
                                      //...nth input

    // NONE: We can modify all outputs after signing.
    tx.outputs().push_back(output_0); //first output
    tx.outputs().push_back(output_1); //second output
                                      //...nth output

    witness empty_witness;      // Only verified in a p2w tx.
    uint64_t prevout_amount(1); // Only verified in a p2w endorsement.

    // Verify input script (and endorsement) for input 0.
    auto ec_input0 = script::verify(tx, input0_index,rule_fork::all_rules,
          input_script0, empty_witness, prevout_script0,
          prevout_amount);

    // Success.
    std::cout << ec_input0.message() << std::endl;

    // Verify input script (and endorsement) for input 1.
    auto ec_input1 = script::verify(tx, input1_index,rule_fork::all_rules,
          input_script1, empty_witness, prevout_script1,
          prevout_amount);

    // Success.
    std::cout << ec_input1.message() << std::endl;


}


int main() {

  std::cout << "Signhash All Example: " << std::endl;
  sign_sighash_all();
  std::cout << "\n";

  std::cout << "Signhash NONE Example: " << std::endl;
  sign_sighash_none();
  std::cout << "\n";

  std::cout << "Signhash SINGLE Example: " << std::endl;
  sign_sighash_single();
  std::cout << "\n";

  std::cout << "Signhash NONE|ANYONECANPAY Example: " << std::endl;
  sign_none_anyonecanpay();
  std::cout << "\n";

  return 0;

}