Ensuring the user cannot register on system even with different email address

Question

I am on creating a system, I am trying to ensure that user cannot register more than once even he uses different email-addresses or he changes its ip, so what strategies should i use ? can I do it with cookies ?

Answer 1

There is nothing you can do to prevent users from registering them multiple times.

User could have:

• Dynamic IP

• Clear cookies

• Clone MAC address

• Use a different email account

• No sane user would purchase additional hardware like biometric authentication

• User could have multiple credit cards, and addresses

The best case, if to forbid the use of multiple accounts, in the TOS/AUP, and delete/ban those accounts.