I write my electrum private seed on the piece of paper and save it with me but i fear that someone near to me may read that paper and get access to the wallet. So i copied the wallet file on my usb and also write the seed in notepad in that usb. Now i want to password protect that usb or encrypt it so if anyone tries to access that usb, he can never open and read it contents. How to do this ?
I have a better more secure solution for this. Since you want to copy your wallet files in your USB and then encrypt that USB so no one can access it. But if you connect your USB with a malware effected computer and copy it is connected to the internet, then you are not 100% sure that your wallet files were not compromised while copying this data on your USB. Even though the chance may be very slim but since we are dealing with our money, we should be 100 sure about it.
A better way is to install a USB operating system on your USB drive, like tails OS and then create an offline Electrum Wallet there and transfer your funds in that wallet. Make your the wifi option is disabled in tails OS and there will be no chance of your seed phrase or wallet file getting compromised or affected by any malware.