账号创建完，私钥丢失，数据还可以被修改么？

[v1xingyue]

describe("Test", () => {
  it("greet", async () => {
    // Create greetings account instruction
    const greetingAccountKp = new web3.Keypair();
    const lamports = await pg.connection.getMinimumBalanceForRentExemption(
      GREETING_SIZE
    );
    const createGreetingAccountIx = web3.SystemProgram.createAccount({
      fromPubkey: pg.wallet.publicKey,
      lamports,
      newAccountPubkey: greetingAccountKp.publicKey,
      programId: pg.PROGRAM_ID,
      space: GREETING_SIZE,
    });

    // Create greet instruction
    const greetIx = new web3.TransactionInstruction({
      keys: [
        {
          pubkey: greetingAccountKp.publicKey,
          isSigner: false,
          isWritable: true,
        },
      ],
      programId: pg.PROGRAM_ID,
    });

    // Create transaction and add the instructions
    const tx = new web3.Transaction();
    tx.add(createGreetingAccountIx, greetIx);

    // Send and confirm the transaction
    const txHash = await web3.sendAndConfirmTransaction(pg.connection, tx, [
      pg.wallet.keypair,
      greetingAccountKp,
    ]);
    console.log(`Use 'solana confirm -v ${txHash}' to see the logs`);

    // Fetch the greetings account
    const greetingAccount = await pg.connection.getAccountInfo(
      greetingAccountKp.publicKey
    );

    // Deserialize the account data
    const deserializedAccountData = borsh.deserialize(
      GreetingSchema,
      GreetingAccount,
      greetingAccount.data
    );

    // Assertions
    assert.equal(greetingAccount.lamports, lamports);

    assert(greetingAccount.owner.equals(pg.PROGRAM_ID));

    assert.deepEqual(greetingAccount.data, Buffer.from([1, 0, 0, 0]));

    assert.equal(deserializedAccountData.counter, 1);
  });
});

以上代码逻辑表示，把创建一个账号和使用账户，结合在一笔交易里边。
如果创建的账号私钥被创建者丢掉了，还可以修改么？

我的理解是，当私钥丢失，该数据只可以通过 connection get 。
无法通过 account 列表传递给rust 合约，因为,传递rust 合约，需要该数据的私钥(已丢失)作为signer 的一部分。