chg: [workshop] LEA and encryption

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Jean-Louis Huynen 2019-11-20 07:23:44 +01:00
parent 67715543e9
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3 changed files with 84 additions and 19 deletions

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@ -251,6 +251,17 @@ codebook to crack it.
\end{frame}
\begin{frame}
\frametitle{Quantifying Security}
RSA 2048 is roughly 100 bits security.
\begin{itemize}
\item
\end{itemize}
\end{frame}
\begin{frame}
\frametitle{Type of encryption}
@ -296,10 +307,10 @@ codebook to crack it.
\frametitle{Encryption Workarounds~\cite{kerr2017}}
\begin{quote}
Any effort to reveal an unencrypted version of a target's data that
has been concealed be encryption.
has been concealed by encryption.
\end{quote}
\begin{itemize}
\item Try to get the key:
\item {\bf Try to get the key:}
\begin{itemize}
\item {\bf Find the key:}
\begin{itemize}
@ -311,8 +322,8 @@ codebook to crack it.
\end{itemize}
\item {\bf Guess the key:},
\begin{itemize}
\item Whereas encryption keys are usually too hard to guess (but more on that
later...),
\item Whereas encryption keys are usually too hard to guess (eg.
128bits security is $2^{128}$ trials (universe is $2^{88}$ ns old)),
\item passphrases are usually shorter to be memorizable, and are
linked to the key,
\item some systems have limitations on sorts of passwords (eg. 4/6
@ -322,27 +333,71 @@ codebook to crack it.
\item dictionaries and password generation rules (\footnote{\url{https://hashcat.net/hashcat/}}).
\item Offline / online attacks (eg. 13 digits pw: 25.000 on an
iphone VS matter of minutes offline),
\item + beware devices protection when online (eg. iphone erase on failure).
\item + beware devices protection when online (eg. iphone erase on repeated failures).
\end{itemize}
\item {\bf Compel the key:}
\begin{figure}
\centering
\includegraphics[width=180px]{security.png}
\end{figure}
\end{itemize}
\item Try to access the PlaintText without the key:
\begin{itemize}
\item Exploit a Flaw,
\item Access Plaintext when in use,
\item Locate Plaintext copy
\end{itemize}
\end{itemize}
{\bf No workaround works every time.}
\begin{figure}
\centering
\includegraphics[width=180px]{security.png}
\end{figure}
\end{itemize}
\item {\bf Try to access the PlainText without the key:}
\begin{itemize}
\item {\bf Exploit a Flaw:}
\begin{itemize}
\item Weakness in the algorithm (more on that later),
\item weakness in the random-number generator (more on that later),
\item weakness in the implementation,
\item bugs (eg. Gordon's exploit on android in
2015\footnote{\url{https://cve.circl.lu/cve/CVE-2015-3860}}),
\item backdoors (eg. NSA NOBUS -Bullrun program- Dual EC-DRBG~\cite{eprint-2015-26238}
\end{itemize}
\item {\bf Access PlainText when in use:}
\begin{itemize}
\item Access live system memory,
\item especially useful against Full Disk Encryption,
\item Seize device while in use,
\item remotely hack the device,
\item ``Network Investigative Technique'' (eg. Playpen case
against tor).
\end{itemize}
\pagebreak
\item {\bf Locate a PlainText copy:}
\begin{itemize}
\item Avoid encryption entirely,
\item cloud providers (eg. emails),
\item remote cloud storage (eg. iCloud),
\end{itemize}
\end{itemize}
\end{itemize}
\vspace{5mm}
{\bf Takeaways:}
\begin{itemize}
\item {\bf No workaround works every time:} the fact that a target used
encryption does not mean that the investigation is over.
\item {\bf some workarounds are expensive:} exploiting.
\item {\bf expertise may be have to be found outside of the
governments:} vendors' assistance?
\end{itemize}
\framebreak
In short, crypto-systems have weaknesses:
Technically, we can retain that crypto-systems have weaknesses:
\begin{itemize}
\item key generation,
\item key length,

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@ -135,4 +135,14 @@
url = {https://doi.org/10.2139/ssrn.2938033},
}
@Article{eprint-2015-26238,
author = {Daniel J. Bernstein and Tanja Lange and Ruben Niederhagen},
title = {Dual EC: A Standardized Back Door},
journal = {IACR Cryptology ePrint Archive},
year = {2015},
volume = {2015},
pages = {767},
url = {https://eprint.iacr.org/2015/767},
}
@Comment{jabref-meta: databaseType:bibtex;}