On: Low Tech Crypto: Solitaire (2020)

[zokier]

There is variant of rc4 called lc4/elsiefour that is intended for computing by hand: https://news.ycombinator.com/item?id=16586257

Found a further variant using deck of cards: https://gitea.blesmrt.net/exa/ls47#alternative-board-with-pl...