diff --git a/talk-slides.pdf b/talk-slides.pdf index 4e03986..bb79d61 100644 Binary files a/talk-slides.pdf and b/talk-slides.pdf differ diff --git a/talk-slides.tex b/talk-slides.tex index 72d5570..c4d79fc 100644 --- a/talk-slides.tex +++ b/talk-slides.tex @@ -178,7 +178,7 @@ communication} \begin{itemize} \item \textbf{E}uropean \textbf{T}elecommunications \textbf{S}tandards \textbf{I}nstitute - \item network technologies used in middle layers: + \item this survey: focus on network technologies used in middle layers: \begin{itemize} \item GeoNetworking for geographical routing \item BTP as transport protocol @@ -202,7 +202,6 @@ communication} \begin{itemize} \item problem: constant communication allows tracking of vehicles \item \textit{linkability} of messages threat to \textit{location privacy} - \item this survey: focus on middle network layers \item linkable identifiers in messages: \begin{itemize} \item vehicle position @@ -249,11 +248,11 @@ communication} \item other nodes present for ambiguity \item coordinated change \item random change frequency - \item all identifiers changed simulataneously, buffers flushed + \item all identifiers changed simultaneously, buffers flushed \end{itemize} \item Car-2-Car CC: divide trips into 3 segments - \item Mix Zones \item Silent Periods + \item Mix Zones \end{itemize} \end{frame} @@ -350,7 +349,7 @@ communication} \begin{frame} - \center\huge{Thank you for your attention} + \center\huge{Thank you for your attention!} \includegraphics[height=0.5\textheight]{figures/nomnompingu.png}\tiny\footnote{CC-BY-SA 3.0 by Elektroll} diff --git a/talk_notes.md b/talk_notes.md new file mode 100644 index 0000000..da4a5fa --- /dev/null +++ b/talk_notes.md @@ -0,0 +1,72 @@ +% notes ITS talk + +- quite a long title, so let's 1st talk about ITS before we get to the Pseudonym Schemes + +## ITS + +- road traffic is still dangerous part of our everyday lives +- infrastructure assist safety +- recent years: decrease of traffic deaths +- probably also thanks to assistance systems + - currently working on their own +- collaboration, proactively broadcast, communicate + +- multiple standardization groups working on it +- survey focuses on middle layers +- GN: geograhical ad-hoc routing, broadcast unicast multicast + +- constant communication, linkability +- location privacy: deriving location patterns of a single user +- authorized senders: message signing + +## pseudonym schemes + +- proposed solution: pseudonyms + - must not be linkable +- we only want authorized vehicles to communicate + +- a priori trusted: RootCA +- EA knows vehicle ID & public key +- AA trusts valid EA certificates +- pseudonym resolution: desirable for law enforcement agencies + +## pseudonym change + +- many strategies have been proposed +- C2C CC: statistical values: + - shall achieve that locations significant to a user can't be linked together nor to the user + - 0.8-1.5km, then each 0.8km or 2-6min +- vehicle-centric change strategies: depending on mobility, trajectory +- density-based +- cryptographic mix zones: symm. key from RSU + - safety of collision avoidance systems + +### advanced schemes + +- identity-based: + - advantage: no certificates needed as ID = key + - disadvantage: splitting mapping information hard, Trusted Authority involved in key derivation +- group signature: + - all members of group can sign for same public key + - problems: group leader, group change -> re-setup of all group keys +- symmetric MACs: + - less computation overhead + - but not really practically usable, as signature checking is done by 3rd parties + +## attacker model + +- single-point: + - communication with EA and AA encrypted, C2C 3 segments (reception range) + - no cooperative change needed +- global passive: + - cooperative change + - cryptographic mix zones sufficient +- active: pseudonym depeltion +- active insider: + - real silent periods needed, crypto mix zones don't work anymore + - servers in the internet can't link IPv6 address thanks to stateless autoconfiguration +- special attacks: + - pseudonym depletion attack + - sybil attack +- privileged: accountability, resolution + - needs independent judicial systems and separation of powers