CADUE: Content-Agnostic Detection of Unwanted Emails for Enterprise Security
Mohamed Nabeel, Enes Altınışık, Haipei Sun, Issa M. Khalil, Hui Wang, Ting Yu · 2021
End-to-end email encryption (E2EE) ensures that an email could only be decrypted and read by its intended recipients. E2EE’s strong security guarantee is particularly desirable for the enterprises in the event of breaches: even if attackers break into an email server, under E2EE no contents of emails are leaked. Meanwhile, E2EE brings significant challenges for an enterprise to detect and filter unwanted emails (spams and phishing emails). Most existing solutions rely heavily on email contents (i.e., email body and attachments), which would be difficult when email contents are encrypted. In this paper, we investigate how to detect unwanted emails in a content-agnostic manner, that is, without access to the contents of emails at all.