Verify Mnemonic
Description
To verify a mnemonic you recorded, you can use the existing-mnemonic command.
Example Usage
Assume you have generated keys from index 0 with the new-mnemonic command, and these are in ./validator_keys.
Generate one key, from the same index, using the existing-mnemonic command, and write the generated files into a separate directory. Then compare the pubkey. If it matches, you correctly recorded the mnemonic.
mkdir -p ./verification_key
./deposit --language english --non_interactive existing-mnemonic --withdrawal_address 0x0000000000000000000000000000000000000000 --chain mainnet --keystore_password WeWontUseThis --compounding --amount 2048 --num_validators 1 --validator_start_index 0 --folder ./verification_key
This creates one validator key as keystore-m_12381_3600_0_0_0-<timestamp>.json in the ./verification_key directory. The command will prompt you for the mnemonic. The deposit_data file won't be used, so we can safely specify a dummy withdrawal address and amount.
Either just look at the two generated files, or use jq (install it first) to generate the pubkey from each:
jq .pubkey ./validator_keys/keystore-m_12381_3600_0_0_0-<timestamp>.json
jq .pubkey ./verification_key/keystore-m_12381_3600_0_0_0-<timestamp>.json
If this pubkey matches, the same mnemonic was used both times.