Galois/Counter Mode (GCM) and GMAC
Video Overview & Insights
There's an updated video at https://www.youtube.com/watch?v=R2SodepLWLg
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104 Galois/Counter Mode (GCM) and GMAC: Get a Gut Level Understanding
GCM does AES-256 encryption and, simultaneously, performs message authentication. View this video to understand how it works.