Leap Encryption Access Project

LEAP Encryption Access Project

Verschlüsselung muss
einfach bereitzustellen sein und leicht benutzbar sein

Tools für sichere Kommunikation im Netz
Dezentralisierung von Service Providern

Verschlüsselung ist nicht einfach

aber, der Ansatz war...

Verschlüsselung muss
einfach bereitzustellen sein und leicht benutzbar sein

also...

lösen wir die harten Probleme

die “großen 7”

Echtheit
Metadaten
Asynchronität
Gruppenproblem
Ressourcen
Verfügbarkeit
Aktualität

Echtheit

Eine Validierung von öffentlichen Schlüsseln ist umständlich für den Nutzer, ohne diese kann man aber kein Vertraulichkeit herstellen.

Nicknym - automatisches finden und validieren von öffentlichen Schlüsseln, transparent!

Metadaten

Heutige Protokolle sind anfällig für Metadatenanalysen/-angriffe, obwohl Metadaten häufig interessanter sind als die Daten selbst.

erzwungenes DNSSEC/DANE

mit einem oder mehreren Optionen:

Automatische Alias-Paare
Onion routing headers
Dropbox eines Dritten
Mixmaster mit Signaturen

- DNSSEC: Short term. Opportunistic TLS for email and chat among servers/providers Effective external observers, no protection of user from provider By itself, potential weaknesses to advanced attacks ( timing, traffic analysis ) In the long term, we plan to adopt one of several different schemes for securely routing meta-data. These include: - Auto alias pairs auto negotiate aliases Advantage: backwards compatible Disadvantage: server stores list of aliases - Onion-routing-headers A message from user A to user B is encoded so that the “to” routing information only contains the name of B’s server. When B’s server receives the message, it unwraps (unencrypts) a supplementary header that contains the actual user “B”. Like aliases, this provides no benefit if both users are on the same server. As an improvement, the message could be routed through intermediary servers. - Third party dropbox To exchange messages, user A and user B negotiate a unique “dropbox” URL for depositing messages, potentially using a third party. To send a message, user A would post the message to the “dropbox”. To receive a message, user B would regularly polls this URL to see if there are new messages. - Mixmaster with signatures Messages are bounced through a mixmaster-like set of anonymization relays and then finally delivered to the recipient’s server. The user’s client only displays the message if it is encrypted, has a valid signature, and the user has previously added the sender to a ‘allow list’ (perhaps automatically generated from the list of validated public keys). For a great discussion comparing mix networks and onion routing, see Tom Ritter’s blog post on the topic.

Asynchronität

Um verschlüsselt zu kommunizieren, muss man sich heute entscheiden zwischen einer vorwärts gerichtete Geheimhaltung (forward secrecy) oder der Möglichkeit asynchron zu kommunizieren

OpenPGP oder OTR
vorläufig: OpenPGP via TLS
langfristig: gemeinsame Entwicklung von neuen kryptografischen Protokollen

With the pace of growth in digital storage and decryption, forward secrecy is increasingly important. Otherwise, any encrypted communication you engage in today is likely to become cleartext communication in the near future. In the example of email and chat, we have OpenPGP with email and OTR with chat: the former provides asynchronous capabilities, and the latter forward secrecy, but neither one supports both abilities. We need both better security for email and the ability to send/receive offline chat messages. In the short term, we are layering forward secret transport for email and chat relay on top of traditional object encryption (OpenPGP). This approach is identical to our stop-gap approach for the meta-data problem, with the one addition that relaying servers need the ability to not simply negotiate TLS transport, but to also negotiate forward secret ciphers and to prevent a cipher downgrade. This approach is potentially effective against external network observers, but does not achieve forward secrecy from the service providers themselves. In the long term, we plan to work with other groups to create new encryption protocol standards that can be both asynchronous and forward secret. : Forward Secrecy Extensions for OpenPGP Triple elliptical curve Diffie-Hellman handshake

Gruppenproblem

In realitas arbeiten Menschen in Gruppen gemeinsam, Public Key Verschlüsselung jedoch nicht.

First we...ummm
Interesting work in secure file backup/sync/sharing (e.g. Wuala and SpiderOak)
Proxy ent- und wiederverschlüsselung
Ring-Signaturen

We have a lot of ideas, but we don’t have any solutions yet to fix this. Essentially, the question is how to use existing public key primitives to create strong cryptographic groups, where membership and permissions are based on keys and not arbitrary server-maintained access control lists. Most of the interesting work in this area has been done by companies working on secure file backup/sync/sharing, such as Wuala and Spideroak. Unfortunately, there are not yet any good open protocols or free software packages that can handle group cryptography. ### There is some free software work on some of interesting building blocks that could be useful in building group cryptography. For example: ### - Proxy re-encryption: See Wikipedia This allows the server to re-encrypt to new recipients without gaining access to the cleartext. The SELS mailing list manager (Secure Email List Services) uses OpenPGP to implement a clever scheme for proxy re-encryption. - Ring signatures: See Wikipedia This allows any member of a group to sign, without anyone knowing which member.

Ressourcenproblem

Es existieren keine freien Protokolle zum gemeinsamen und sicheren arbeiten an Ressourcen.

Yap, wir haben nichts :/
"Read-write-web", meet ["Group problem" solution here]
Auch hier: der meiste Fortschritt geschieht im Bereich Dateisynchronisierung

For example, when using secure chat or secure federated social networking, you need some way to link to external media, such as an image, video or file, that has the same security guarantees as the message itself. Embedding this type of resource in the messages themselves is prohibitively inefficient. We don’t have a proposal for how to address this problem. There are a lot of great initiatives working under the banner of read-write-web, but these do not take encryption into account. In many ways, solutions to the resource problem are dependent on solutions to the the group problem. As with the group problem, most of the progress in this area has been by people working on encrypted file sync (e.g. strategies like Lazy Revocation and Key Regression).

Verfügbarkeit

Nutzer möchten ungehindert die Geräte wechseln und ihre Daten wiederherstellen können nach z. B. einem Geräteverlust. Dies auf sichere Art und Weise zu tun ist sehr schwierig.

Soledad - Synchronisierung von (lokal) verschlüsselten Daten zwischen verschiedenen Geräten
puuh! Da haben wir genug Ideen gehabt!

Aktualität

Generell sind Software-Aktualisierungen anfällig für Angriffe.

Thandy (thanks, Tor!)

The sad state of update security is especially troublesome because update attacks can now be purchased off the shelf by repressive regimes. The problem of software update is particular bad on desktop platforms. In the case of mobile and HTML5 apps, the vulnerabilities are not as dire, but the issues are also harder to fix. To address the update problem, LEAP is adopting a unique update system called Thandy from the Tor project. Thandy is complex to manage, but is very effective at preventing known update attacks. Thandy, and the related TUF, are designed to address the many security vulnerabilities in existing software update systems. In one example, other update systems suffer from an inability of the client to confirm that they have the most up-to-date copy, thus opening a huge vulnerability where the attacker simply waits for a security upgrade, prevents the upgrade, and launches an attack exploiting the vulnerability that should have just been fixed. Thandy/TUF provides a unique mechanism for distributing and verifying updates so that no client device will install the wrong update or miss an update without knowing it. Related to the update problem is the backdoor problem: how do you know that an update does not have a backdoor added by the software developers themselves? Probably the best approach is that taken by Gitian, which provides a “deterministic build process to allow multiple builders to create identical binaries”. We hope to adopt Gitian in the future.

Für User

Bitmask-Client für Mac OS, Linux, Android (Windows kommt)

Für Provider

Automatisierung Installation und Konfiguration der Dienste
Sichere Crypto-Voreinstellungen (TLS Parameter, etc)

leap-platform

Puppet-Rezepte für Konfiguration der Server


									# smtp TLS                                                                    
									postfix::config {                                                             
										'smtp_use_tls':        value  => 'yes';                                     
										'smtp_tls_CApath':     value  => '/etc/ssl/certs/';                         
										'smtp_tls_CAfile':     value  => $ca_path;                                  
										'smtp_tls_cert_file':  value  => $cert_path;                                
										'smtp_tls_key_file':   value  => $key_path;                                 
										'smtp_tls_ask_ccert':  value  => 'yes';                                     
										'smtp_tls_loglevel':   value  => '1';                                       
										'smtp_tls_exclude_ciphers':                                                 
										value => 'aNULL, MD5, DES';                                               
										# upstream default is md5 (since 2.5 and older used it), we force sha1      
										'smtp_tls_fingerprint_digest':                                              
										value => 'sha1';                                                          
										'smtp_tls_session_cache_database':                                          
										value => 'btree:${queue_directory}/smtp_cache';                           
										'smtp_tls_security_level':                                                  
										value  => 'may';                                                          
										# see issue #4011                                                           
										'smtp_tls_protocols':                                                       
										value => '!SSLv2, !SSLv3';                                                
									}

Provider Config

Server Layout, IPs, Kontaktdaten, etc


									$ cat provider.json 
									//
									// General service provider configuration.
									//
									{
										"domain": "example.org",
										"name": {
											"en": "example"
										},
										"description": {
											"en": "You really should change this text"
										},
										"contacts": {
											"default": "admin@example.org"
										},
										"languages": ["en"],
										"default_language": "en",
										"enrollment_policy": "open"
									}

									$ cat nodes/web1.json 
									{
										"ip_address": "99.231.92.23",
										"services": "webapp",
										"tags": "production"
									}

Leap-cli

Kommandozeilen Tool für Admins


									$ leap --yes deploy
									Deploying to these nodes: web1, vpn1, couch1
									= updated hiera/couch1.yaml
									= updated hiera/web1.yaml
									= checking node 
									- [web1] ok
									- [couch1] ok
									- [vpn1] ok
									= synching configuration files
									- hiera/web1.yaml -> web1:/etc/leap/hiera.yaml
									- hiera/vpn1.yaml -> vpn1:/etc/leap/hiera.yaml
									- hiera/couch1.yaml -> couch1:/etc/leap/hiera.yaml
									- files/branding/tail.scss, files/branding/head.scss -> web1:/etc/leap
									= synching puppet manifests
									- /home/demo/leap/demo/leap_platform/[bin,puppet] -> web1:/srv/leap
									- /home/demo/leap/demo/leap_platform/[bin,puppet] -> vpn1:/srv/leap
									- /home/demo/leap/demo/leap_platform/[bin,puppet] -> couch1:/srv/leap
									...

Setting up a new Provider

Initializing and deploying nodes

Dienste

Encrypted Internet Proxy aka VPN

Chat (in Arbeit)

Dienste in Planung

Client-encrypted Filehosting

Voip

Kollaborativer Texteditor

Provider online

Bitmask.net - Referenz-Provider von Leap

demnächst offen für beta-Tester

interessierte Provider

The Calyx Institute

...

Etc

Website: https://leap.se

Github Mirror: https://github.com/leapcode

Gemacht mit reveal.js