Use cases for WebCrypto API

Hi, all.

I gathered most of use cases for web crypto API from public-identity and
this mailinglist. They were classfied by categories in charter for
http://www.w3.org/2011/11/webcryptography-charter.html#id-other-deliverables.
Please feel free to edit and comment!

http://www.w3.org/2011/11/webcryptography-charter.html

c.f. *This draft was origniated from WebCrypto API community group
http://www.w3.org/community/webcryptoapi/wiki/Use_Cases under discussion:
please see
http://lists.w3.org/Archives/Public/public-identity/2011Dec/0033.html*

Channy
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Mozilla Korea Community, http://www.mozilla.or.kr
Technology Evangelist, Daum Developers Network & Affiliates
http://dna.daum.net