Under the Hood of DANE Mismanagement in SMTP

Hyeonmin Lee, Md Ishtiaq Ashiq, Moritz Müller, Roland van Rijswijk-Deij, Taekyoung (Ted) Kwon, Taejoong Chung

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

2 Citations (Scopus)
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The DNS-based Authentication of Named Entities (DANE) is an Internet security protocol that enables a TLS connection without relying on trusted third parties like CAs by introducing a new DNS record type, TLSA. DANE leverages DNSSEC PKI to provide the integrity and authenticity of TLSA records. As DANE can solve security challenges in SMTP, such as STARTTLS downgrade attacks and receiver authentication, it has been increasingly deployed surpassing more than 1 M domains with SMTP servers that have TLSA records. A recent study, however, reported that there are prevalent misconfigurations on DANE SMTP servers, which hinders DANE from being proliferated.

In this paper, we investigate the reasons why it is hard to deploy and manage DANE correctly. Our study uses large-scale, longitudinal measurements to study DANE adoption and management, coupled with a survey of DANE operators, some of which serve more than 100 K domains. Overall, we find that keeping the TLSA records from a name server and certificates from an SMTP server synchronized is not straightforward even when the same entity manages the two servers. Furthermore, many of the certificates are configured to be reissued automatically, which may result in invalid TLSA records. From surveying 39 mail server operators, we also learn that the majority keeps using CA-issued certificates, despite this no longer being required with DANE, since they are worried about their certificates not being trusted by clients that have not deployed DANE. Having identified several operational challenges for correct DANE management, we release automated tools and shed light on unsolved challenges.

Original languageEnglish
Title of host publicationProceedings of the 31st USENIX Security Symposium, Security 2022
PublisherUSENIX Association
Number of pages16
ISBN (Electronic)9781939133311
Publication statusPublished - 2022
Event31st USENIX Security Symposium, Security 2022 - Boston Marriott Copley Place, Boston, United States
Duration: 10 Aug 202212 Aug 2022
Conference number: 31


Conference31st USENIX Security Symposium, Security 2022
Country/TerritoryUnited States


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