Privacy technologies support the provision of online services while protecting user privacy. Cryptography lies at the heart of many such technologies, creating remarkable possibilities in terms of functionality while offering robust guarantees of data confidential- ity. The cryptography literature and discourse often represent that these technologies eliminate the need to trust service providers, i.e., they enable users to protect their privacy even against untrusted service providers. Despite their apparent promise, privacy technolo- gies have seen limited adoption in practice, and the most successful ones have been implemented by the very service providers these technologies purportedly protect users from.
The adoption of privacy technologies by supposedly adversarial service providers highlights a mismatch between traditional models of trust in cryptography and the trust relationships that underlie deployed technologies in practice. Yet this mismatch, while well known to the cryptography and privacy communities, remains rela- tively poorly documented and examined in the academic literature— let alone broader media. This paper aims to fill that gap.
Firstly, we review how the deployment of cryptographic tech- nologies relies on a chain of trust relationships embedded in the modern computing ecosystem, from the development of software to the provision of online services, that is not fully captured by tra- ditional models of trust in cryptography. Secondly, we turn to two case studies—web search and encrypted messaging—to illustrate how, rather than removing trust in service providers, cryptographic privacy technologies shift trust to a broader community of secu- rity and privacy experts and others, which in turn enables service providers to implicitly build and reinforce their trust relationship with users. Finally, concluding that the trust models inherent in the traditional cryptographic paradigm elide certain key trust relation- ships underlying deployed cryptographic systems, we highlight the need for organizational, policy, and legal safeguards to address that mismatch, and suggest some directions for future work.
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An Empirical Analysis of the Commercial VPN Ecosystem
Global Internet users increasingly rely on virtual private network (VPN) services to preserve their privacy, circumvent censorship, and access geo-filtered content. Due to their own lack of technical sophistication and the opaque nature of VPN clients, however, the vast majority of users have limited means to verify a given VPN service’s claims along any of these dimensions. We design an active measurement system to test various infrastructural and privacy aspects of VPN services and evaluate 62 commercial providers. Our results suggest that while commercial VPN services seem, on the whole, less likely to intercept or tamper with user traffic than other, previously studied forms of traffic proxying, many VPNs do leak user traffic—perhaps inadvertently—through a variety of means. We also find that a non-trivial fraction of VPN providers transparently proxy traffic, and many misrepresent the physical location of their vantage points: 5–30% of the vantage points, associated with 10% of the providers we study, appear to be hosted on servers located in countries other than those advertised to users.
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- Award ID(s):
- 1705050
- NSF-PAR ID:
- 10100952
- Date Published:
- Journal Name:
- Proceedings of the Internet Measurement Conference (IMC'18)
- Page Range / eLocation ID:
- 443 to 456
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1145/3278532.3278570
