Source of SipHash

[[Hash]]

- https://131002.net/siphash/

- SipHashとAdvanced Hash Flooding
--  http://causeless.seesaa.net/article/307716879.html

- Hash-flooding DoS と SipHash
--  http://d.hatena.ne.jp/kazu-yamamoto/20130805/1375692951

- SipHashについてのメモ
--   https://qiita.com/hnw/items/d72815e2d45f898d9184