If I saved my view key and spend key can I recover my wallet if my mnemonic seed is lost?

Question

I accidentally deleted by my wallet file and mnemonic seed. Can I recover my wallet with my view key and spend key? If yes, then how do I do so?

Answer 1

Yes, it is possible to restore your account with just the view and spend keys.

monero-wallet-cli has the --generate-from-keys <name> option, which will create a wallet with the given name, and prompt the user for: address, spendkey and viewkey.

Example:

$ monero-wallet-cli --generate-from-keys myWallet
Monero 'Helium Hydra' (v0.11.1.0-release)
Logging to monero-wallet-cli.log
Standard address: 45FofLeGb1oAR7fDhrNsmvHHxjaY3at6YLxHq7S9YvQ54sMSn6BxtHe9tKYKfQm1YgE4WUyhLcMPiCJ17LQAtnjAQA3Nmh4
Secret spend key: 4941baf224dc238d7329a8c9ef672b3340ccb26eaf460f6c4cc8afa97a735a0c
Secret view key: 8fc685263e28604ebca23e2877e0847d034dc380db3ba800238a481b8719ea09
Enter new wallet password: 
Confirm Password: 
Generated new wallet: 45FofLeGb1oAR7fDhrNsmvHHxjaY3at6YLxHq7S9YvQ54sMSn6BxtHe9tKYKfQm1YgE4WUyhLcMPiCJ17LQAtnjAQA3Nmh4
Restore from specific blockchain height (optional, default 0),
or alternatively from specific date (YYYY-MM-DD): 2017-11-25
Restore height is: 1450154
Is this okay?  (Y/Yes/N/No): Y
Starting refresh...
Refresh done, blocks received: 1419                             
Balance: 0.000000000000, unlocked balance: 0.000000000000
Background refresh thread started
[wallet 45FofL]:

If you don't remember your standard address, then there's a sligtly more complicated way, the --generate-from-json option. You then have to create a small JSON file with that information, called, data.json, for instance:

{
  "version": 1,
  "filename": "restoredwallet.bin",
  "password": "some string",
  "viewkey": "abcdabcd...",
  "spendkey": "1234124..."
}

Then:

./monero-wallet-cli --generate-from-json data.json

Once your wallet is recreated, you can view its reconstructed seed with the command:

seed

(only if viewkey is deterministic, non-deterministic wallets don't have seeds)

Answer 2

You can recover the wallet with this simplewallet command:

--generate-from-keys

Answer 3

I tested simplewallet’s --generate-from-json option, using only the spendkey and the viewkey, and as expected, it worked. However, from Luigi's address test page, I learnt that the "Private View Key" is simply derived (Keccak-256 followed by "sc_reduce32") from the "Hexadecimal Seed", which is identical to the "Private Spend Key". Therefore, it is really beyond my comprehension why the --generate-from-json option is requiring the viewkey as well? Without the viewkey in the JSON file, simplewallet returns:

Error: At least one of Electrum-style word list and private view key
must be specified

For cold storage purposes, I would much rather depend on the actual 64 character hexadecimal spendkey, than on a 75 character mnemonic (counting only 25 times the first 3 letters), which I guess no one can (or would risk to) remember anyway, for which the dictionary or the algorithm might also change over time. In my opinion, the --generate-from-json option should just drop the viewkey requirement, and calculate it instead.

Using Luigi's website, one can obtain the viewkey from the spendkey:

1. Type the spendkey in the field "2. Hexadecimal Seed:".
2. Click on the button Gen 3. & 4..
3. Copy the viewkey from the field "4. Private View Key:".

Although, I feel that the above isn't a reliable option, as it adds an external dependency. And more importantly, one shouldn't post their spendkey online to recover a (cold storage) wallet.

Edit: It appears that, at least using Safari on OS X, one can save the web page as a .webarchive file, and then perform the above steps while being offline.