That's no guarantee of security. Its a good idea of course but someone can hack your computer as the result of a security flaw that you aren't even aware, hack Alaska or any number of other entry points.

985X's suggestion is an excellent one. If a redemption looks suspicious require the account holder to validate it. At a minimum all redemptions should be acknowledged with an email and text to the account holder asking to confirm the order or say it wasn't them (just like credit card companies do for charges that don't appear legit). It also seems like a good idea to limit close in redemptions to the account holder, those already listed or put the request on a pending status until the account holder confirms their identity.

There are lots of ways to handle this that aren't difficult nor unduly inconvenient for a user. They could even make the higher level of security opt in. That way if someone didn't and their account was hacked it would be on them.