It's generally not considered conflict of interest, as the boards transcend single institutions and their members tend to be individuals in the stage of career where their individual reputations that matter more than the reputation of the institution they "represent".
The hard part in this is remaining silent and pretending you don’t know anything about this, when you meet your peers at conferences.
Even if all these clues could be effectively removed, the nature of the research work, tools used, writing style, all unambiguously indicate authorship to someone in the field. I think for this reason double-blind review is not popular.
Which is not to say that it would be great if it were possible...
See the "anonymity" section.