Additional data for anonymous submission I've recently submitted a paper to a conference requiring anonymous submission, meaning that the name of the authors should not be included, and no obvious self-reference should be made. The problem is that I add additional information relevant to the submission, such as some proofs and some code working on an example, calculating some numerical data (that could be found on the paper, but requiring some effort). 

For a non anonymous submission, I would have published a technical report with all the proofs, cited the report in the submission, hosted the code on my website, and put a link to it. However, since the technical report would not have been anonymous and since my website is obviously linking to me, it was not possible. 

Concerning the proofs, I managed to put them in the appendix, explaining that they were only intended for the reviewing process, but I could not find any solution for the code. The conference submission site (easychair) did not provide any way to input additional data. What's the best way to deal with this kind of situations?
There are three criteria: the solution must obscure your identity, it must not allow you to learn anything about the reviewers, and the second criterion must be common knowledge.

Any attempt to distribute files yourself through the web will fail to satisfy these conditions.  For example, if you use a website you own (under a pseudonym, say), then you can inspect the logs.  Even if you have arranged to use a service that will not provide any logs or allow you to tag pages or link to outside services, the reviewers may not notice that you have done so, and they may not even be willing to believe that you are not doing something tricky.

So this is a problem you cannot solve yourself.  You should get in touch with the program committee chair and ask whether the committee could make this data available to the reviewers.  As long as it goes through them, it doesn't matter how they provide it.