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LEAP: A Next-Generation Client VPN and Encrypted Email Provider

Part of the Lecture Notes in Computer Science book series (LNSC,volume 10052)


As demonstrated by the revelations of Edward Snowden on the extent of pervasive surveillance, one pressing danger is in the vast predominance of unencrypted messages, due to the influence of the centralizing silos such as Microsoft, Facebook, and Google. We present the threat model and architectural design of the LEAP platform and client applications, which currently provisions opportunistic email encryption combined with a VPN tunnel and cross-device synchronization.


  • Encryption
  • Email
  • VPN

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  • DOI: 10.1007/978-3-319-48965-0_11
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    To try, follow instructions on

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    Such as Thunderbird, Evolution, or Outlook.

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    Note that parts of Sect. 3 are modified versions of material available on the LEAP wiki at

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    The Android version tends to lag behind development compared to the Linux version due to the design having to be re-coded in Java.

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    See work by Debian on reproducible builds that LEAP is applying to its code:

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    Details at

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    The source code for Pixelated is available here:


  1. Dingledine, R., Mathewson, N., Syverson, P.: Tor: the second-generation onion router. In: Proceedings of the 13th USENIX Security Symposium, p. 2 (2004)

    Google Scholar 

  2. Foster, I.D., Larson, J., Masich, M., Snoeren, A.C., Savage, S., Levchenko, K.: Security by any other name: on the effectiveness of provider based email security. In: Proceedings of the 22nd ACM SIGSAC Conference on Computer and Communications Security, pp. 450–464. ACM (2015)

    Google Scholar 

  3. Garfinkel, S.L.: Enabling email confidentiality through the use of opportunistic encryption. In: Proceedings of the 2003 Annual National Conference on Digital Government Research, dg.o ’03, pp. 1–4. Digital Government Society of North America (2003)

    Google Scholar 

  4. Melara, M.S., Blankstein, A., Bonneau, J., Felten, E.W., Freedman, M.J., Coniks: Bringing key transparency to end users. In: 24th USENIX Security Symposium (USENIX Security 15), pp. 383–398 (2015)

    Google Scholar 

  5. Samuel, J., Mathewson, N., Cappos, J., Dingledine, R.: Survivable key compromise in software update systems. In Proceedings of the 17th ACM Conference on Computer and Communications Security, CCS 2010, pp. 61–72. ACM, New York (2010)

    Google Scholar 

  6. Unger, N., Dechand, S., Bonneau, J., Fahl, S., Perl, H., Goldberg, I., Smith, M.: Sok: Secure messaging. In: 2015 IEEE Symposium on Security and Privacy, pp. 232–249. IEEE (2015)

    Google Scholar 

  7. Whitten, A., Tygar, J.D.: Why Johnny can’t encrypt: a usability evaluation of pgp. 5.0. In: Proceedings of the 8th Conference on USENIX Security Symposium, vol. 8, SSYM’99, pp. 14. USENIX Association, Berkeley (1999)

    Google Scholar 

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The authors are supported by NEXTLEAP (EU H2020 ref: 688722) and the Open Technology Fund.

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Correspondence to Harry Halpin .

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© 2016 Springer International Publishing AG

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Sparrow, E., Halpin, H., Kaneko, K., Pollan, R. (2016). LEAP: A Next-Generation Client VPN and Encrypted Email Provider. In: Foresti, S., Persiano, G. (eds) Cryptology and Network Security. CANS 2016. Lecture Notes in Computer Science(), vol 10052. Springer, Cham.

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