Topic: Best approach for generating cryptocurrency's wallets in web application (Read 159 times)

I'm designing web application architecture with cryptocurrency payments. Users of this web application must be deposit their accounts directly to the unique wallet in my web application. The question is how to generate wallet for each user in web application if I want to use not only Bitcoin but Litecoin, Ethereum, Zcash etc.

My first point of view was - third-party API usage like blockcypher.com, but blockcypher.com don't support lots of cryptocurrencies and when I generate wallet I keep private keys in blockcypher.com infrastructure.

The second point of view was - use my own full node of cryptocurrency client on the server and create a wallet for users through it on my server, but I think it isn't secure and it is very heavy for the server because the full node has a huge volume of GB and I need lots of nodes for every cryptocurrency.

The third point of view was - create wallets without third-party API and full nodes of cryptocurrency but use libraries for it like Nethereum or NBitcoin and keep private keys on my server. The last variant I like more than others but I don't know how to do it enough secure for a web application.

Please answer me about my ideas or give a new one. I need an opportunity add new cryptocurrency to my application and generate wallets for a deposit for each user and control every transaction from users to my web application. I want only approach to generate, keep, support new cryptocurrencies, control internal transactions to my web application.