あまり自信はありませんが、自前で勝手にするというニュアンスでself-imposedかなと思いましたが、本物でないということでpseudoというのもいかがでしょうか。

Nanchatte=imitiation; ninsho=authentication see In order for this mixed model authentication scenario to work, and also to make it ... and to extract those roles, and mimic a forms authentication process. ...
www.15seconds.com/issue/050203.htm and: I don't run vBulletin on my site (maybe in the future), but I would like to mimic their authentication since it seems like a robust software ...
www.devcomments.com/How-to-mimic-vBulletin-type-authenticat...

Essentially なんちゃって is colloquial expression for "self-claimed", "on one's own judgment", or "arbitrarily made" assertions.

As for "認証", I think your choice of authentification sounds good as this is in IT context.

HTH

According to the example given on http://www.uniadex.co.jp/nextalk/special/sp2002_08.html , a water company database is being used for authentication purposes by other business and municipal agencies. By supplying this information, it acts as a third-party data supplier.

I think people here are making a big deal out of 「なんちゃって」. Although it has the connotation of "BS (or cheapskate) Authentication," I do not think it needs to be translated because the idea of third-party authentication isn't so bad in the Western world AFAIK.

It is a form of authorization, where you could authorize yourself by showing a prior authorization, such as a historical record of your payment of your water bill.

For example, if you wanted to get an account at a local library, and they need proof of your residence. So if they accept your utility bill as a proof, and you get authorized, the process of you being authorized by this method is called なんちゃって認証.

「なんちゃって」 is colloquial language; the equivalent in English is "whatever", "blah blah", "so-and-so", "something or other"

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Note added at 10 hrs (2010-08-25 03:50:38 GMT)
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...add an apostrophe in there "it's".

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Note added at 1 day16 hrs (2010-08-26 09:44:20 GMT)
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Change to "Fake Certification" if you don't mind.

Some leg-pulling by one of the Beach Boys has stimulated me into carrying out a bit of research. 「なんちゃって」, as well as being 「若者言葉」as above, has taken on the meaning of "fake" or "copied".

Sorry, I'm a bit behind on this...too much red-eyeing it with all night translations zzz...

With なんちゃって being slang, the English translation should also reflect the slangy tone of the original Japanese phrase in http://blog.koss.jp/category_internet/1/article_147.html

So a thesaurus lookup of "fake" turned up sham, bogus, flimflam etc. I chose the most slangy that also tries to accurately reflect the playfully deriding tone of the original Japanese text. It also helps that the original English version of the Japanese translated article (http://jp.techcrunch.com/archives/20081230md5-collision-crea... referenced by Joyce uses "bogus certification authority" as well.

Original English article of Japanese article referenced by Joyce:
http://www.crunchgear.com/2008/12/30/md5-collision-creates-r...

The author of the blog post is criticizing how the Japanese government is trying to start its own certificate authority without running it in the proper fashion. Now what does that mean? We need some technical background on what a certificate authority is and what its used for.

I'm not an expert but I have generated my own key pairs and setup web servers to use SSL encryption (https://wiki.archlinux.org/index.php/LAMP#SSL). Without going too much into the intricacies of public key encryption, anyone can generate their own public/private key pairs for encrypted data communications between two parties. These are basically text files with coded strings of text generated with an algorithm. These keys not only serve to encrypt but also uniquely identify the sender. But since these keys can be generated by anyone (if you know of software to generate them for you), how do you really know the key you receives is from who they say they are? This is where a 3rd party certification agent comes in to vouch that the sender is who they say they are and is a trusted person or institution that has registered and proven themselves to the certificate authority. If you're dealing with a bank web site, you want to make sure the site's encryption keys have been preregistered with a trusted certification authority (Verisign) or else you could be giving your account login and personal info to a rogue site that collects your data for less than kosher purposes. Visiting the rogue site will also probably involve DNS hacking to replace the bank server's IP with the rogue site's in some manner but we won't get into that.

The author of the blog is rolling his eyes at the Japanese government that is creating its own certificate authority without properly verifying the keys registered with it. The government is trying to use the encryption feature of the keys without the 3rd party verification of identity to provide trust that is the purpose of a certificate authority and so he playfully derides the technical cluelessness of the government in his blog article by saying they're setting up "bogus certs".

I do not pretend the technical information I gave is completely accurate but for the purposes of translating the phrase in question I think it is probably enough.