hedera-sdk-js: Mnemonics -> ECDSA key -> ECDSA key doesn't yield same public key

Description

I’m recovering a private key from Mnemonics and printing the public key as a string. I then use the private key string above to instantiate a PrivateKey and print its public key as a string. The two public keys differ, yet printing both private keys as string yield the same result, see example below

Steps to reproduce

import {
    Mnemonic, PrivateKey,
} from "@hashgraph/sdk";

async function test() {
    const mnemonic = await Mnemonic.fromString("hamster produce dry base sunny bubble disease throw cricket garden beyond script");
    const privateKey = await mnemonic.toEcdsaPrivateKey();

    const privateKeyString = privateKey.toStringRaw();
    const publicKeyString = privateKey.publicKey.toStringRaw();

    // Restore from string
    const restoredPrivateKey = PrivateKey.fromStringECDSA(privateKeyString);
    const restoredPrivateKeyString = privateKey.toStringRaw();
    const restoredPublicKeyString = restoredPrivateKey.publicKey.toStringRaw();

    const results = {
      FromMnemonics: {Private: privateKeyString, Public: publicKeyString},
      ECDSA: {Private: restoredPrivateKeyString, Public: restoredPublicKeyString}
    };
    console.table(results);

}

test();

outputs

┌───────────────┬────────────────────────────────────────────────────────────────────┬──────────────────────────────────────────────────────────────────────┐
│    (index)    │                              Private                               │                                Public                                │
├───────────────┼────────────────────────────────────────────────────────────────────┼──────────────────────────────────────────────────────────────────────┤
│ FromMnemonics │ '63167e08a41aaaa8226945b999a201f789e1a362d4d5b93d605e0841795eb500' │ '0322c1cc8bdbdd54b851251a61ea98d4da31f2749f00e44d66efc2295df76b4a9a' │
│     ECDSA     │ '63167e08a41aaaa8226945b999a201f789e1a362d4d5b93d605e0841795eb500' │ '0283ddc3dfca5dab9c10b4a6be831bae1b50ab36224c305bdd008c6042b34b3123' │
└───────────────┴────────────────────────────────────────────────────────────────────┴──────────────────────────────────────────────────────────────────────┘

Shouldn’t both public keys be the same ?

Note, investigating through debugging the SDK shows that the two private keys differ slightly, see below

First key (from mnemonics - chaincode attribute value removed)

{ "_key": { "_keyPair": { "privateKey": { "type": "Buffer", "data": [ 99, 22,
126, 8, 164, 26, 170, 168, 34, 105, 69, 185, 153, 162, 1, 247, 137, 225, 163,
98, 212, 213, 185, 61, 96, 94, 8, 65, 121, 94, 181 ] }, 
"publicKey": { "type":
"Buffer", "data": [ 3, 34, 193, 204, 139, 219, 221, 84, 184, 81, 37, 26, 97,
234, 152, 212, 218, 49, 242, 116, 159, 0, 228, 77, 102, 239, 194, 41, 93, 247,
107, 74, 154 ] } }
  }

Second key (fromStringECDSA)

Second _key { "_keyPair": { "privateKey": { "type": "Buffer", "data": [ 99, 22,
126, 8, 164, 26, 170, 168, 34, 105, 69, 185, 153, 162, 1, 247, 137, 225, 163,
98, 212, 213, 185, 61, 96, 94, 8, 65, 121, 94, 181, 0 ] },
"publicKey": {
"type": "Buffer", "data": [ 2, 131, 221, 195, 223, 202, 93, 171, 156, 16, 180,
166, 190, 131, 27, 174, 27, 80, 171, 54, 34, 76, 48, 91, 221, 0, 140, 96, 66,
179, 75, 49, 35 ] } }, "_chainCode": null
}

note that the first contains an extra element at the end of the buffer 0, the public key buffer is vastly different.

Additional context

No response

Hedera network

mainnet, testnet, previewnet

Version

v2.19.1 and 2.19.0

Operating system

None