What the heck is AEAD again?

28 Apr, 2025 Here’s a problem you might be familiar with: I keep forgetting what AEAD exactly means and why you would ever use it. Yes, I know the acronym stands for “Authenticated Encryption with Associated Data”, but does that really clarify anything? Not to me, so I’ve finally decided to sit down and write this blog post as a piece of help for my future self… and for anyone else who finds AEAD hard to retain. Why bother at all? Simply put, AEAD encryption is the current industry standard. That sounds like a good reason to bother, at least if you care about Understanding Your Building Blocks. You don’t have to take my word for it, though. Below are some relevant data points: In TLS 1.3 , released in 2018, “all ciphers are modeled as Authenticated Encryption with Associated Data (AEAD)” (see RFC 8446). , released in 2018, “all ciphers are modeled as Authenticated Encryption with Associated Data (AEAD)” (see RFC 8446). Following TLS, the QUIC protocol (which underlies HTTP/3 ), re ... Read full article.