Design secure our crypto-currency wallet project

Project Description I am searching an experienced architect to design and secure our crypto-currency wallet We need online secure wallet for members to manage their Bitcoin, Ethereum… token with Database (will decide together). The members can buy Bitcoin, Ether… with usd, eur… and exchange coins. A reference wallet is CoinBase. We want to be simple and flexible in use, I mean, we can use our wallet in all the plateform like windows, android and ios with secure way. Functions: Users have to register first as a member with their email and create a password for their account, Users must then input additional registration data such as their name etc. They will then also need to confirm their account with the link given to their email in order to use the account. After the activation, user can login to member area/dashboard. Then register/verify their personal information by giving official documents like passport or ID cards. On the user first login, the script will automatically generate Bitcoin and Ethereum Wallet Address for this user, based on their email & password. Then display member Area for example on the member area there will be Main Functions: 1. Show Bitcoin or Ethereum Address & Ethereum Balance 2. Send Token or Ether to another Bitcoin or Ethereum Address 3. Check transaction on Blockchain 4. Reporting and transaction history (IN and OUT transaction) 5. Download/Backup user Wallet Private key and Keystore JSON File 6. logout Link 7. Activate the two-step, three-step login Etc etc. We will discuss about it more in detail on chat.