Keystroke timing obfuscation added to ssh(1) - https://news.ycombinator.com/item?id=37307708 - Aug 2023 (255 comments)
also:
Timing Analysis of Keystrokes and Timing Attacks on SSH (2001) [pdf] - https://news.ycombinator.com/item?id=18557916 - Nov 2018 (17 comments)