> For the complete documentation index, see [llms.txt](https://http3-explained.haxx.se/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://http3-explained.haxx.se/ja/why-quic/why-secure.md).

# セキュア

QUIC は常にセキュアです。

平文版のプロトコルが存在しないので、QUIC コネクションをネゴシエートすることは TLS 1.3 を用いて暗号化とセキュリティを行うことと同義です。

上記のように、(拡張性を損なうという意味での) 硬直化や他の種類のブロックと特別な処理を防ぐと同様に、QUIC は Web ユーザーが望んでいた HTTPS のセキュアなプロパティを全て備えています。

暗号化プロトコルがネゴシエートされる前に、平文で送信されるわずかな初期ハンドシェイクパケットがあるのみです。


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