mxcl/homebrew — pull request #12611 by LoonyPandora (2012-06-06 00:06:28+00:00)
Title: Nginx: Use SHA-256 checksums instead of MD5

MD5 is vulnerable, and no longer appropriate as a checksum. See discussion in #12587 and example of possible attack: http://www.mscs.dal.ca/~selinger/md5collision/