1. You must use SSL. Even if you just want to secure your application against your clueless neighbor. That is a minimum of $40.
2. You must decrypt the response on an account with NTFS access to the private key. The NT Network Service account is not likely to have read access to the private key on a hosted account. Good luck explain how and getting co-operation from your hosting provider.
3. Decryption must be done under FULL TRUST. Many hosted accounts only let you run in medium trust and don’t let you create COM+ dlls, put stuff in the GAC, etc.
[Items 2 and 3 might not even be a good idea. If the world at large manages to use your web application to maliciously download your SSL cert, I suppose they could do something evil, like pretend they are you]
4. To get rid of the “the website isn’t secure for banking or ecommerce” you have to spend $1000 on an EV SLL cert. Oh, sure, pocket change.
5. And who is issuing managed cards? I can get an SSL based cert from Thawte that says I am the person that controls my email account, but I can’t find anyone who issues managed infocards anywhere.
I’ve about realize that I–a computer profession and programmer, will not be able to implement InfoCard/Cardspace in any form, not for my blog, not for my hobby website, nothing. Either one has $1040 and ones own entire server or nothing.
If only the top 10 biggest websites can overcome the hurdles posed by infocard, what we are going to see is 5 websites accept infocard and everyone else (mom & pop websites) continue to use passwords and user ID’s. InfoCard will have a minimal impact on how authentication is done.
This is going to drive small websites into using OpenId. Consumer will rapidly gain a few dozen OpenId cards. The rising ubiquity of OpenId–which doesn’t try to be a waterproof authentication method–will take over the world, relegating InfoCard to “that way you logon to Live.com services”.
Come on Microsoft, when are we going to be able to run CardSpace/Info card in “real world” mode?
[Thanks to Self-issued.info for the logo] [Actually, I take that back, it is a Microsoft trademark. The purple box is has a substantial amount of IP self legislation that goes with it. According to MS's lawyers, I am currently in violation of usage guide lines for the icon. Let's see how Microsoft silences critics of InfoCard.]