2 \gdef\currentsectionname{GPG}
3 \gdef\currentsubsectionname{GnuPG}
6 \footnote{\url{https://tools.ietf.org/search/rfc4880}}
7 uses asymmetric encryption to protect a session key which is used to encrypt a message. Additionally, it signs messages via asymmetric encryption and hash functions. %% what? - azet
8 Research on SHA-1 conducted back in 2005\footnote{\url{https://www.schneier.com/blog/archives/2005/02/sha1\_broken.html}} has made clear that collision attacks are a real threat to the security of the SHA-1 hash function. PGP settings should be adapted to avoid using SHA-1.
11 When using PGP, there are a couple of things to take care of:
13 \item keylengths (see section \ref{section:keylengths})
14 \item randomness (see section \ref{section:RNGs})
15 \item preference of symmetric encryption algorithm (see section \ref{section:CipherSuites})
16 \item preference of hash function (see section \ref{section:CipherSuites})
19 Properly dealing with key material, passphrases and the web-of-trust is outside of the scope of this document. The GnuPG website\footnote{\url{http://www.gnupg.org/}} has a good tutorial on PGP.
21 This \href{https://www.debian-administration.org/users/dkg/weblog/48}{Debian How-to} is a great resource on upgrading your old PGP key as well as on safe default settings. This section is built based on the Debian How-to.
23 \subsubsection{Hashing}
24 Avoid SHA-1 in GnuPG. Edit \$HOME/.gnupg/gpg.conf:
26 \configfile{gpg.conf}{208-210}{Digest selection in GnuPG}
28 Before you generate a new PGP key, make sure there is enough entropy available (see subsection \ref{subsec:RNG-linux}).
30 %\subsubsection{PGP / GPG Operations}
32 %% Ciphering - Unciphering operations
33 %%% TOO COMPLEX. Make a pointer to a good GPG tutorial
35 %% Signing / checking signatures
36 %%% TOO COMPLEX. Make a pointer to a good GPG tutorial
38 %\subsubsection{Trusted Keys}
40 %%Explain that a key by himself is not trustable. Chain of trust principle.
42 %%% TOO COMPLEX. Make a pointer to a good GPG tutorial
44 %\subsection{Available implementations and mails plugins}
46 %% Microsoft Windows (Symantec for Outlook? GnuPG + ....)
47 %%% TOO COMPLEX. Make a pointer to a good GPG tutorial
49 %% Linux (GnuPG + Enigmail for Thunderbird)
51 %%% TOO COMPLEX. Make a pointer to a good GPG tutorial
52 %% Mac OS X (GnuPG + GPGMail)
53 %%% TOO COMPLEX. Make a pointer to a good GPG tutorial