epic/pirg "cryptoparty" email security presentation by michael carbone (access), 10/25/13

7/27/2019 EPIC/PIRG "Cryptoparty" email security presentation by Michael Carbone (Access), 10/25/13

1/28

Email Security

The base protocol for email (SMTP) wasnever designed with security in mind

You are effectively sending postcards! Security mechanisms can be added

Confidentialityof email communications

can be improved through the use ofPGPGPG tools

Protecting metadata (contacts locations) iseven more difficult


2/28

Anonymity orConfidentiality?

"re you #nown already as a person of interestto adversaries with some control over thenetwor# infrastructure$ Andis your account

associated with you$ "nonymity already lost

%ill the use of strong cryptography (PGP) itselfidentify you as a person of interest$

&se 'TTPS as 'TTPS traffic is common

PGP encrypted email is for confidentiality

Toris a tool for anonymity torproectorg


3/28

Email SecurityFeatures


4/28


5/28

Different EncryptionSystems


6/28


7/28

TECHNOLOGY USED SECURITY OF MESSAGES ANONYMITY

SMTP 'eaders * +ontent unencrypted(,in theclear-) in networ#

None(sender *recipient #nown)

%ebmail ('TTP) 'eaders * +ontent sent through networ#stored by provider unencrypted

None (sender *recipient #nown)

e!mail " SS#$T#S%&TT'S(

"ll encryptedbut cryptosystem relies ontru)t of pro*iderand provider storescontent unencrypted .ecipient maylea# message unencrypted depending

on their provider

Some(sender #nown.ecipient toprovider issues)

%ebmail * SS/T/S('TTPS) * Tor

"ll encrypted but webmail providerstores content unencrypted

Full anonymity(unlessproviderrecipientcompromised)

SMT' " 'G'$G'G 'eaders unencrypted +ontent

encrypteddecrypted locally

None(sender *

recipient #nown)SMT' " IMA'$T#S "'G'$G'G

"ll encryptedwith T/S but relies on trustof provider Content encrypted locally

Some(sender #nown)

SMT' " IMA'$T#S "'G'$G'G " Tor

"ll encrypted 'eaders stored withprovider unencrypted Content

encryptedlocally

Full anonymity(unless provider

compromised)


8/28

PGP encrypted

email over SSL/TLS


9/28


10/28

Weakest Link Issues- End Recipient


11/28


12/28

server-to-serverencryption of

webmail providers

Modifiedfrom01ash#2n


13/28


14/28

TECHNOLOGY USED SECURITY OF MESSAGES ANONYMITY

SMTP 'eaders * +ontent unencrypted(,in theclear-) in networ#

None(sender *recipient #nown)

%ebmail ('TTP) 'eaders * +ontent sent through networ#stored by provider unencrypted

None (sender *recipient #nown)

e!mail " SS#$T#S%&TT'S(

"ll encryptedbut cryptosystem relies ontru)t of pro*iderand provider storescontent unencrypted .ecipient maylea# message unencrypted depending

on their provider

Some(sender #nown.ecipient toprovider issues)

%ebmail * SS/T/S('TTPS) * Tor

"ll encrypted butwebmail providerstores content unencrypted

Full anonymity(unlessproviderrecipientcompromised)

SMT' " 'G'$G'G 'eaders unencrypted+ontent

encrypteddecrypted locally

None(sender *

recipient #nown)SMT' " IMA'$T#S "'G'$G'G

"ll encryptedwith T/S but relies on trustof provider Content encrypted locally

Some(sender #nown)

SMT' " IMA'$T#S "'G'$G'G " Tor

"ll encrypted 'eaders stored withprovider unencrypted Content

encryptedlocally

Full anonymity(unless provider

compromised)


15/28

Providers and

Trust 3o you trust your email provider$ Google$

Microsoft$ Yahoo$

Should you trust them with your emailcontent$

Should you trust them with your contact

and location data (metadata)$ %hat legal urisdiction are they under$


16/28


17/28

Alternativeemail providers

4onprofit email providers

.iseupnet

"utisticiorg ("ssocia5ione 6nvestici)

+ommericial providers based outside the &S

7astmailfm

M/"Ts can still provide access to user data0 'ushmail

89ncrypted 9:Mail +ompany 'ushmail Spills to 7eds8Wired,;


18/28

Weakest Link Issues- Physical Security


19/28

Data at Rest

issues PGP protects the content of your emails if0

Your email account is compromised

Your computer is stolen or confiscated yourdis# is copied you are stopped at a bordercrossing etc and your data is forensically

e?amined


20/28

PGP Gotchas

4ever give away sensitive information inthe subect line of the email

Saving of draft emails to provider

9nsure you mar# your message to beencrypted @97A.9 you start typing thecontent of the email


21/28

Digital Signatures

and Email +ontent is verifiable from the Sender

6dentify of the Sender is not guaranteed!

"lways sign emails that contain lin#s "lways sign attachments

+ontent has not been modified in transit

4on:repudiation Sender cannot redact the email and its content


22/28

Attachments

METHOD P.AP9.T69S

PGP the file * Sign the file *+reate the email * "ttach file *"ttach the signature file

'eaders * 9mail +ontent in the clear"ttachment encrypted and "ttachmentsigned

PGP the file * Sign the file *+reate the email * Set email toPGP * "ttach file * "ttach thesignature file

'eaders in the clear 9mail +ontent and"ttachment encrypted and signed"ttachment name in the clear

+reate the email * Set email to

PGPM6M9 PGP Sign * "ttachfile

'eaders in the clear 9mail +ontent and

"ttachment encrypted and signed


23/28


24/28

Gotchas

4ever give away sensitive information inthe name of an attachment onlyPGPM6M9 protects the name ofattachments


25/28

The Risk /

Security Equation "ttaining an appropriate level of security in

a near:infinite space of vulnerability

9?pending the minimum amount of energyand resources to raise the bar beyond the

level of energy and resources youradversaries would be willing to commit


26/28

Further resources

Security in a +o,

step:by:step instructions for installing programs

https0securityinabo?org

by Tactical Tech and 7rontline 3efenders

Encryption or-)

more conte?t on different programs

https0pressfreedomfoundationorgencryption:wor#s

by the 7reedom of the Press 7oundation


27/28

Thanks!

Mic.ael Car!one

michael1accessnoworg

+rian /u00anduggan1newamericanet

1oe &all

oe1cdtorg#i!!y Reini).

libby1fsforg
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


28/28

Hands-on!

7irst ma#e sure you have networ#!

Second install GnuPG Thunderbird

9nigmail 'oping you8ve done this already!

https0wwwenigmailnetdocumentationBuic#startphp

Generating a #eys sending to #eyserver Send first signed emailC encrypted email

Abtain #ey (securely) from others
https://www.enigmail.net/documentation/quickstart.phphttps://www.enigmail.net/documentation/quickstart.php

epic/pirg "cryptoparty" email security presentation by michael carbone (access), 10/25/13

Documents