KNUDSEN, Lars Ramkilde. A pictorial illustration of conventional cryptography. DAIMI Report Series, [S. l.], v. 23, n. 490, 1994. DOI: 10.7146/dpb.v23i490.6985. Disponível em: https://tidsskrift.dk/daimipb/article/view/6985. Acesso em: 7 dec. 2025.