To cite package ‘cyphr’ in publications use:

  FitzJohn R (2025). _cyphr: High Level Encryption Wrappers_. R package
  version 1.1.7, <https://CRAN.R-project.org/package=cyphr>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {cyphr: High Level Encryption Wrappers},
    author = {Rich FitzJohn},
    year = {2025},
    note = {R package version 1.1.7},
    url = {https://CRAN.R-project.org/package=cyphr},
  }