US visa policy impedes science
Xioayun Wang is a professor at Shandong University, China. She is one of the leading cryptographers of today; she helped break (well, not quite break, but drastically reduce the complexity of) MD5, SHA0, and SHA1 hash functions. Thanks to her, projects that currently rely on MD5 and SHA1 for verification of data (like BitTorrent, Portage, GNU Arch, etc.) will soon have to move to more secure hash functions. On August 15, she was scheduled to give the keynote presentation at Crypto 2005, where she was to present her finding that SHA1 complexity has been reduced to 263 (SHA1 was originally believed to have complexity of 280, which is secure. By contrast, 263 can be realistically broken by today’s computers.)
But she didn’t get to present. She could not obtain a US visa. (Officially, she was not refused a visa; she simply received no response from the US embassy by the time the conference started).
The utter bone-headedness of the decision not to grant one of the greatest scientists in her field — not some random graduate student — a visa to present her findings to US scientists — not steal US national secrets — boggles the mind. I see only two explanations. Either the Department of State, DHS, or whoever gives out visas is less competent than a basket-case third-world bureaucracy; or the US government has made a conscious decision that it does not care about scientific progress. For the sake of this country, I hope it is the former and not the latter.