See also
Sub rosa (Neo-Latin for "under the rose") is a Latin phrase which denotes secrecy or confidentiality. The rose has an ancient history as a symbol of secrecy.
In Hellenistic and later Roman mythology, roses were associated with secrecy because Cupid gave a rose to Harpocrates (the Hellenistic god of silence) so he would not reveal the secrets of Venus. [1] Banquet rooms were decorated with rose carvings, reportedly as a reminder that discussions in the rooms should be kept in confidence. [1]
This was inherited in later Christian symbolism, where roses were carved on confessionals to signify that the conversations would remain secret. [1]
The phrase entered the German language (unter der Rose) and, later, the English language, both as a Latin loan phrase (at least as early as 1654) and in its English translation. [1]