How does exchange like Spectro does ?

[csmtcy]

I wondering the function like spectro, when i deposit ethereum into the spectro, it will create a new wallet for my account.

After i convert the token to others it will auto do transfer from the wallet to a contract.

From what i know, the web3.js solidity able to create account, but every action include transactions should require the private key to complete.

Thats mean we should store the private key on the server to do the function ?

Thanks.

[bob123]

I wondering the function like spectro, when i deposit ethereum into the spectro, it will create a new wallet for my account.
After i convert the token to others it will auto do transfer from the wallet to a contract.
From what i know, the web3.js solidity able to create account, but every action include transactions should require the private key to complete.
Thats mean we should store the private key on the server to do the function ?

Spectro (assuming you are talking about spectrocoin.com) seems to be a 'normal' wallet / exchange.
The private keys are stored on their server. Basically you don't own anything until you withdraw it to an address you have the private key of.
After you deposit your tokens/coins the exchange is in full charge of your coins and is going to merge funds occasionally hence the movement of your tokens.

If you want to store coins/token i would highly suggest to use a wallet where (only) you have access to your private keys.

[csmtcy]

Thanks for clearing my doubts, because when come to security concern. I always thinking there is anyway better to achieve the same thing without storing the private key on server.

Do you know any way to keep the private key save ? I'm not good at security.

Thanks.

[bob123]

Do you know any way to keep the private key save ? I'm not good at security.

After purchasing any coins/tokens withdraw them to your personal (desktop-/hardware-) wallet.

The safest option to store your coins would be a paper wallet. Its the best option for storing long term and when you don't access your funds often.
A hardware wallet is not much less secure than a paper wallet. It combines the positive effects of having an offline storage with the benefits of being able to spend the funds easily.
The downsides of hardware wallets are their price (50$+).

Webwallets / Keeping coins at exchanges are the worst option to choose from.
Cryptocurrencies are invented to be a trustless system. When you trust an exchange/web wallet to store your coins your destroying the sense of crypto and the reason it is made for.
Just additional negative factors, no real benefits.