Secure Web-Based Multi-Crypto Cold Wallet

I'm looking for a developer to create a secure, web-based cold wallet that supports Bitcoin, Ethereum, and Litecoin.

Key features required:
- Secure storage
- Multi-signature support
- Backup and restore options

Ideal skills and experience:
- Expertise in cryptocurrency security
- Experience in developing secure web applications
- Knowledge of multi-signature wallet functionality
- Strong background in backup and recovery systems


There should be a page or panel at the back where we can see all fiat money transactions deposited with the administrator password.

1. We can use the integrations we have specified. 2. Transaction limits do not need to be applied after identity verification kyc. 3. There will be no deposit fee, only the withdrawal fee can be set to 1 usdt + network fee. 4. We need to automatically convert the fiat money deposited via bank transfer into $Tether in the wallet.

Please provide portfolios and relevant experience.