To cite package ‘ciphertext’ in publications use:

  Annicchiarico L (2025). _ciphertext: Classical Cryptography Methods
  for Words and Phrases_. R package version 0.2.0,
  <https://github.com/luigi-annic/ciphertext>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {ciphertext: Classical Cryptography Methods for Words and Phrases},
    author = {Luigi Annicchiarico},
    year = {2025},
    note = {R package version 0.2.0},
    url = {https://github.com/luigi-annic/ciphertext},
  }