Recovery of monero address and private view and spend keys using MyMonero's mnemonic seed

How to recover address, private view and spend keys in C++ based on 13 word mnemonic seed provided by MyMonero.

MyMonero uses 13 word mnemonic seed, which cant be used in the Monero's simplewallet. The reason is, that the simplewallet uses 25 word mnemonic seed, and also, generation of private view and spend keys by the simplewallet is different than that used by MyMonero.

More information on the differences between the simplewallet and mymonero, can be found:

• Cryptnote Tests
• Why MyMonero key derivation is different than for the simplewallet (Mnemonic)

The example was prepared and tested on Xubuntu 15.10 x64 and Monero 0.9.

Instruction for Monero 0.9 compilation and setup of Monero's header files and libraries are at:

• Compile Monero 0.9 on Ubuntu 15.10 and 14.04 x64

C++: main.cpp

int main(int ac, const char* av[]) {

    // get command line options
    xmreg::CmdLineOptions opts {ac, av};

    auto help_opt = opts.get_option<bool>("help");

    // if help was chosen, display help text and finish
    if (*help_opt)
    {
        return 0;
    }

    // default language for the mnemonic
    // representation of the private spend key
    string language {"English"};

    // get 13 word mnemonic seed from MyMonero
    auto mnemonic_opt = opts.get_option<string>("mnemonic");

    // get the program command line options, or
    // some default values for quick check
    string mnemonic_str = mnemonic_opt
                          ? *mnemonic_opt
                          : "slid otherwise jeers lurk swung tawny zodiac tusks twang cajun swagger peaches tawny";

    cout << "\n"
         << "Mnemonic seed    : " << mnemonic_str << endl;


    // change the MyMonero 13 word mnemonic seed
    // to its 16 byte hexadecimal version
    xmreg::secret_key16 hexadecimal_seed;

    // use modified words_to_bytes function.
    xmreg::ElectrumWords::words_to_bytes(mnemonic_str, hexadecimal_seed, language);

    cout << "\n"
         << "Hexadecimal seed : " << hexadecimal_seed << endl;


    // take the 16 byte hexadecimal_seed, and
    // and perform Keccak hash on it. It will
    // produce 32 byte hash.
    crypto::hash hash_of_seed;

    cn_fast_hash(hexadecimal_seed.data, sizeof(hexadecimal_seed.data), hash_of_seed);

    cout << "\n"
         << "Hash of seed     : " << hash_of_seed<< endl;


    // having the hashed seed, we can proceed
    // with generation of private and public spend keys.
    // the keccak hash of the seed is used as a seed
    // to generate the spend keys.
    crypto::public_key public_spend_key;
    crypto::secret_key private_spend_key;

    crypto::generate_keys(public_spend_key, private_spend_key,
                          xmreg::get_key_from_hash<crypto::secret_key>(hash_of_seed),
                          true);

    cout << "\n"
         << "Private spend key: " << private_spend_key << "\n"
         << "Public spend key : " << public_spend_key  << endl;

    // now we get private and public view keys.
    // to do this, we keccak hash the hash_of_seed again
    crypto::hash hash_of_hash;
    cn_fast_hash(hash_of_seed.data, sizeof(hash_of_seed.data), hash_of_hash);

    crypto::public_key public_view_key;
    crypto::secret_key private_view_key;


    crypto::generate_keys(public_view_key, private_view_key,
                          xmreg::get_key_from_hash<crypto::secret_key>(hash_of_hash),
                          true);

    cout << "\n"
         << "Private view key : " << private_view_key << "\n"
         << "Public view key  : " << public_view_key  << endl;



    // having all keys, we can get the corresponding monero address
    cryptonote::account_public_address address {public_spend_key, public_view_key};


    cout << "\n"
         << "Monero address   : " << address << endl;


    cout << "\nEnd of program." << endl;

    return 0;
}

Example 1

./mymonero  -m "slid otherwise jeers lurk swung tawny zodiac tusks twang cajun swagger peaches tawny"

Result:

Mnemonic seed    : slid otherwise jeers lurk swung tawny zodiac tusks twang cajun swagger peaches tawny

Hexadecimal seed : <5878efd0a6d45b0374b49c000da07cd2>

Hash of seed     : <6d23fe14606a0d5fe62d05a78c4b5b1cae2f38f9330e42e86a50286db16ad61e>

Private spend key: <804f08b84507fb0610910d04ae517c07ae2f38f9330e42e86a50286db16ad60e>
Public spend key : <b54264728412c71bb62caca5b3cb57eb96a48a580c97a65257290243e3adf401>

Private view key : <dbb024c981cf7dc797593713f5f426c3b1cad50542c0814d4786e12e768be504>
Public view key  : <75fc0c90732a3db632bc0a169328067fa3f4c52e80ae067aa60bae8c4ccd8711>

Monero address   : <48VWHdLTEpE5dqa5VpAy5xgQWBHZARiGmEmojNLqD4ef1FAzkPxCe9JXUYwCShRR5XNMGnyusrnkmMWr2HMdfDRx2vsrG7c>

The private keys agree with those generated by MyMonero.

Example 2

./mymonero  -m "nearby hover hiker renting giddy purged chrome paddles point tsunami hoax pledge point"

Result:

Mnemonic seed    : nearby hover hiker renting giddy purged chrome paddles point tsunami hoax pledge point

Hexadecimal seed : <fbdf0efd70ff3c5a321e0f0969041948>

Hash of seed     : <a16321b78892ff31facf9070f33eb445e2510bfd0e45e86891264771de5884f4>

Private spend key: <bef8b944fdc3eb086b9f0ee4e79aa30ce1510bfd0e45e86891264771de588404>
Public spend key : <39812cdb0d7f29bc8c70c319cb381b8f943b9a3fa35d40f59e93b63edd012605>

Private view key : <8952f17e4378c74fcd99ed6c70e799db60a601edf2685407087cc8c06d4db808>
Public view key  : <fb227e0e28539fd6ca13fc7d5b2da19307665ae0d152eb87b1239a00c6c66b07>

Monero address   : <43oVy226ybWYYA93SExWoLR1tznhhaXRqi5pLtYWhcM3212LriHRkLecvj6zoehqkLRbN9P18LDBGPhP9fHHY7Ar1qi9QDM>

The private keys agree with those generated by MyMonero.

Example 3

./mymonero  -m "suddenly opus governing mystery divers obvious royal icon hefty nautical boxes among boxes"

Result:

Mnemonic seed    : suddenly opus governing mystery divers obvious royal icon hefty nautical boxes among boxes

Hexadecimal seed : <852249bca4446e65501cc7f8338027ec>

Hash of seed     : <30c0dc774aef038b78079f2478cf89d14f2d75c0a02bda4c5dbb14ce2913b97c>

Private spend key: <b5f423ed913983229cbdd9af61fa703f4f2d75c0a02bda4c5dbb14ce2913b90c>
Public spend key : <2c78b799c4d26a2dabb5ceaaff07efff9bd9ffc08cbc9b17634800019f3ca641>

Private view key : <601e6488942149980d9cd50298ef7cdb623cc58e8045f70de994faaea0a97a0e>
Public view key  : <7e9d7fcf3e20a8a3a02f0d73dd676dcc80d0d45c7efdd7d9c783453df150cca3>

Monero address   : <43JrWR7mQYh8e4gLAhVeXpjkj5b4RePpv4utgkFt7bpRBxP1t5J4wQKUNNiapRubXSbCwMLZDJ9CJdRjV1m26Kz3KRB4iFJ>

The private keys agree with those generated by MyMonero.

How can you help?

Constructive criticism, code and website edits are always good. They can be made through github.

Some Monero are also welcome:

48daf1rG3hE1Txapcsxh6WXNe9MLNKtu7W7tKTivtSoVLHErYzvdcpea2nSTgGkz66RFP4GKVAsTV14v6G3oddBTHfxP6tU