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Implicit Accounts

Background​

Implicit accounts work similarly to Bitcoin/Ethereum accounts.

  • They allow you to reserve an account ID before it's created by generating a ED25519 key-pair locally.
  • This key-pair has a public key that maps to the account ID.
  • The account ID is a lowercase hex representation of the public key.
  • An ED25519 Public key contains 32 bytes that maps to 64 characters account ID.
  • The corresponding secret key allows you to sign transactions on behalf of this account once it's created on chain.

Specifications​

Creating an account locally​

For a purpose of this demo, we'll use the betanet network.

Set betanet network​

export NEAR_ENV=betanet

Generating a key-pair first​

near generate-key tmp1

Example Output

Generated key pair with ed25519:BGCCDDHfysuuVnaNVtEhhqeT4k9Muyem3Kpgq2U1m9HX public key

It generates a key-pair for tmp1 account ID. The new public key is ed25519:BGCCDDHfysuuVnaNVtEhhqeT4k9Muyem3Kpgq2U1m9HX.

NEAR's string representation of a public key is <curve>:<data>.

  • Curve is either ed25519 or secp256k1. For implicit accounts we only support ed25519.
  • Data is a base58 encoding of the public key. For ed25519 it contains 32 bytes.

This command generated a key-pair locally and stored it locally at:

~/.near-credentials/betanet/tmp1.json

Viewing the key-pair​

Run this command to print the content of the key-pair file:

cat ~/.near-credentials/betanet/tmp1.json

Content:

{"account_id":"tmp1","public_key":"ed25519:BGCCDDHfysuuVnaNVtEhhqeT4k9Muyem3Kpgq2U1m9HX","private_key":"ed25519:4qAABW9HfVW4UNQjuQAaAWpB21jqoP58kGqDia18FZDRat6Lg6TLWdAD9FyvAd3PPQLYF4hhx2mZAotJudVjoqfs"}

As you can see, it's a valid json-file and public key matches the one we generated. The private_key is a secret/private key of the key pair that can be used to sign transactions with the corresponding public key.

Converting a public key to an account ID.​

Let's convert a public key from NEAR string representation ed25519:BGCCDDHfysuuVnaNVtEhhqeT4k9Muyem3Kpgq2U1m9HX

The easiest way is to use near-cli with interactive console repl

1) Start near repl:

near repl

2) Store your base58 public key to a local constant:

const pk58 = 'ed25519:BGCCDDHfysuuVnaNVtEhhqeT4k9Muyem3Kpgq2U1m9HX'

3) Now let's parse the public key and convert it to the hex in one line:

nearAPI.utils.PublicKey.fromString(pk58).data.toString('hex')

The output string is the account ID in hex (without '):

'98793cd91a3f870fb126f66285808c7e094afcfc4eda8a970f6648cdf0dbd6de'

Now the new account ID is 98793cd91a3f870fb126f66285808c7e094afcfc4eda8a970f6648cdf0dbd6de.

4) We can now give this account ID to someone and ask them to transfer tokens.

Moving the temporary key-pair​

Finally, we need to move tmp1.json key-pair to the real account ID, so that near-cli can use it to sign transactions.

Let's first export our account ID to a bash env variable:

export ACCOUNT="98793cd91a3f870fb126f66285808c7e094afcfc4eda8a970f6648cdf0dbd6de"

Now we can move the tmp1.json file:

mv ~/.near-credentials/betanet/tmp1.json ~/.near-credentials/betanet/$ACCOUNT.json

NOTE: While .json key-pair file still contains the "account_id":"tmp1", it's okay. Because near-cli doesn't care.

Assuming you've received tokens on your new account, you can transfer from it using the following command:

near $ACCOUNT <receiver> <amount>

You can also replace $ACCOUNT with your actual account ID, e.g.

near send 98793cd91a3f870fb126f66285808c7e094afcfc4eda8a970f6648cdf0dbd6de <receiver> <amount>

Transferring to the implicit account​

Let's say someone gives you their account ID 0861ea8ddd696525696ccf3148dd706c4fda981c64d8a597490472594400c223. You can just transfer to it by running:

near send <your_account_id> 0861ea8ddd696525696ccf3148dd706c4fda981c64d8a597490472594400c223 <amount>

BONUS: Converting public key using python (for learning purposes)​

For this flow we'll use python3 (with version 3.5+) with base58 library.

You can install this library with pip3:

pip3 install --user base58

Start python3 interpreter:

python3

The first thing is to get the data part from the public key (without ed25519: prefix). Let's store it in a variable pk58:

pk58 = 'BGCCDDHfysuuVnaNVtEhhqeT4k9Muyem3Kpgq2U1m9HX'

Now let's import base58:

import base58

Finally, let's convert our base58 public key representation to bytes and then to hex:

base58.b58decode(pk58).hex()

Output:

'98793cd91a3f870fb126f66285808c7e094afcfc4eda8a970f6648cdf0dbd6de'

This gives us the same account ID as near-cli, so this is encouraging.

Note: The default network for near-cli is testnet. If you would like to change this to mainnet or betanet, please see near-cli network selection for instructions.

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