Differences

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--- project:secure_remailer:start [2017/06/05 19:28] – ruza
+++ project:secure_remailer:start [2017/06/06 16:48] (current) – [Solutions] ruza
@@ Line 19: / Line 19: @@
 We have an **contact email** where people can send sensitive info. We dont want to transfer such info unsecurely nor have stored anywhere where can be leaked later. This email addres is actually an alias whose membership is changing overtime. Only actual final recipients (ie brmlab council members) should be able to decrypt such email.
-==== Solution ====
+==== Solutions ====
 === GnuPG email/ML gateway ===
@@ Line 52: / Line 52: @@
     * email should be dropped, rejected or delivered (and stored in the archive) untouched
-= Mailing list archive =
+== Mailing list archive ==
 Emails are stored in the email archive in a decrypted form. Since there is no requirement to reencrypt emails to the specific recepients an email archive is the only reason to hold private subkey on the receiving server.
@@ Line 63: / Line 63: @@
 Recipient always receives an mailing list processed emails in the form of GnuPG encrypted email and using private subkey to decrypt such email.
+As we know in our situation (brmlab council mailing list) consist of:
+  * council members
+  * brmlab members interested in council activities
 == Master keypair owners ==
@@ Line 70: / Line 74: @@
   * __public subkey distribution__ on **email sender** site - since subkey is generated with one year validity (technically 12-15 months) an email clients needs to refresh to currently valid keyring state at least once a year.
   * __private subkey distribution__ on **email recipients** site - each time new subkey generated (Usually related to the list of newly elected board members) this new subkey needs to be distributed to board members
-  * Afaik in GnuPG there is no way how to generate an decrypt only subkey (key without signing capability). Since we have an requirement to decrypt email content for the purpose of storing it in the mailing list archive an receiving email server needs to hold a private subkey currently used. The question whether processing server should also keep expired subkeys could be a matter of discussion.
+  * Using [[wp>GnuPG]] expert mode there is possibility to generate **"encrypt only" subkey** (key without signing and authentication capabilities) [[https://www.sidorenko.io/blog/2014/11/04/yubikey-slash-openpgp-smartcards-for-newbies/|howto]]. Since we have an requirement to decrypt email content for the purpose of storing it in the mailing list archive an receiving email server needs to hold a private subkey currently used. The question whether processing server should also keep expired subkeys could be a matter of discussion. [[https://www.cs.cornell.edu/courses/cs5430/2015sp/notes/rsa_sign_vs_dec.php|RSA Signing is Not RSA Decryption]]
 ==== Old idea ====
-<note>Due to a change in the idea on implementation and architecture the following text needs to be reworked.</note>
+<note>Due to a change in the idea on implementation and architecture the following text needs to be reworked or proclaimed as not selected as a solution to be implemented.</note>
 Sender encrypts an email against Brmlab public GPG key. Email is delivered to an brmlab SMTP server, reencrypted by **GPG-remailer** to an up-to-date list of recipients (that is changed more frequently than contact email) and resent to them. Only actual and specific members can decrypt such message with his/her own private key.