載入中... 相關課程 Back Part 1: 介紹密碼學 (英) 登入觀看 ⇐ Use this menu to view and help create subtitles for this video in many different languages. You'll probably want to hide YouTube's captions if using these subtitles. Part 1: 介紹密碼學 (英) : 簡單解釋為什麼我們需要密碼 上傳學習單 下載學習單