multipart/encrypted
aes128gcm
AEAD_AES_128_GCM
[1] Crypto Law Survey ( (2013-02-25 18:41:34 +09:00 版)) http://www.cryptolaw.org/
[2] IAB Statement on Internet Confidentiality | Internet Architecture Board (2015-05-03 15:25:32 +09:00 版) https://www.iab.org/2014/11/14/iab-statement-on-internet-confidentiality/