MOST IMPORTANT RULE:
if the web address doesn't start with https (the s being the important part) it is not a secure site. Never type any information in unless you see the https. Even if the website says secure or your browser says it is always good to check for the https.
i did go to
www.treasurydirect.com and it took me to
https://www.auctions.zionsdirect.com/ which is a secure site but i have never heard nor known anyone that has heard of them. I would research it more to make sure it is safe. the site is secure so a hacker cant take your money when it is being sent but doesn't mean the site cant take it once they have it. Not saying this site will because like i said i have never heard of them. Just saying make sure you look into it, thats all.