Merge branch 'master' into master-android
This commit is contained in:
Evgeny Poberezkin
commit
f27de052cf
10
README.md
10
README.md
@ -232,6 +232,8 @@ You can use SimpleX with your own servers and still communicate with people usin
|
||||
|
||||
Recent and important updates:
|
||||
|
||||
[Nov 25, 2023. SimpleX Chat v5.4 released: link mobile and desktop apps via quantum resistant protocol, and much better groups](./blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md).
|
||||
|
||||
[Sep 25, 2023. SimpleX Chat v5.3 released: desktop app, local file encryption, improved groups and directory service](./blog/20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.md).
|
||||
|
||||
[Jul 22, 2023. SimpleX Chat: v5.2 released with message delivery receipts](./blog/20230722-simplex-chat-v5-2-message-delivery-receipts.md).
|
||||
@ -366,13 +368,13 @@ Please also join [#simplex-devs](https://simplex.chat/contact#/?v=1-2&smp=smp%3A
|
||||
- ✅ Message delivery confirmation (with sender opt-out per contact).
|
||||
- ✅ Desktop client.
|
||||
- ✅ Encryption of local files stored in the app.
|
||||
- 🏗 Using mobile profiles from the desktop app.
|
||||
- ✅ Using mobile profiles from the desktop app.
|
||||
- 🏗 Improve experience for the new users.
|
||||
- 🏗 Post-quantum resistant key exchange in double ratchet protocol.
|
||||
- 🏗 Large groups, communities and public channels.
|
||||
- Message delivery relay for senders (to conceal IP address from the recipients' servers and to reduce the traffic).
|
||||
- Post-quantum resistant key exchange in double ratchet protocol.
|
||||
- Large groups, communities and public channels.
|
||||
- Privacy & security slider - a simple way to set all settings at once.
|
||||
- Improve sending videos (including encryption of locally stored videos).
|
||||
- Improve experience for the new users.
|
||||
- SMP queue redundancy and rotation (manual is supported).
|
||||
- Include optional message into connection request sent via contact address.
|
||||
- Improved navigation and search in the conversation (expand and scroll to quoted message, scroll to search results, etc.).
|
||||
|
||||
@ -208,7 +208,7 @@ struct ConnectDesktopView: View {
|
||||
Section("Found desktop") {
|
||||
Text("Waiting for desktop...").italic()
|
||||
Button {
|
||||
disconnectDesktop(.dismiss)
|
||||
disconnectDesktop()
|
||||
} label: {
|
||||
Label("Scan QR code", systemImage: "qrcode")
|
||||
}
|
||||
|
||||
@ -120,11 +120,11 @@
|
||||
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||||
5CE2BA702845308900EC33A6 /* SimpleXChat.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 5CE2BA682845308900EC33A6 /* SimpleXChat.framework */; };
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@ -408,11 +408,11 @@
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5CD67B932B11416600C510B1 /* libffi.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; path = libffi.a; sourceTree = "<group>"; };
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5CD67B942B11416600C510B1 /* libgmp.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; path = libgmp.a; sourceTree = "<group>"; };
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5CD67B952B11416700C510B1 /* libgmpxx.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; path = libgmpxx.a; sourceTree = "<group>"; };
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5CD67B9B2B120ADF00C510B1 /* libgmp.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; path = libgmp.a; sourceTree = "<group>"; };
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5CD67B9C2B120ADF00C510B1 /* libgmpxx.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; path = libgmpxx.a; sourceTree = "<group>"; };
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5CD67B9D2B120ADF00C510B1 /* libHSsimplex-chat-5.4.0.6-9DfazyElTA72omjHp0C93u.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; path = "libHSsimplex-chat-5.4.0.6-9DfazyElTA72omjHp0C93u.a"; sourceTree = "<group>"; };
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5CD67B9F2B120ADF00C510B1 /* libffi.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; path = libffi.a; sourceTree = "<group>"; };
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5CDCAD492818589900503DA2 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
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@ -521,13 +521,13 @@
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5CD67BA12B120ADF00C510B1 /* libgmpxx.a in Frameworks */,
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5CD67BA22B120ADF00C510B1 /* libHSsimplex-chat-5.4.0.6-9DfazyElTA72omjHp0C93u.a in Frameworks */,
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5CE2BA93284534B000EC33A6 /* libiconv.tbd in Frameworks */,
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5CD67BA02B120ADF00C510B1 /* libgmp.a in Frameworks */,
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runOnlyForDeploymentPostprocessing = 0;
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@ -589,11 +589,11 @@
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5C764E5C279C70B7000C6508 /* Libraries */ = {
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5CD67B9E2B120ADF00C510B1 /* libHSsimplex-chat-5.4.0.6-9DfazyElTA72omjHp0C93u-ghc8.10.7.a */,
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path = Libraries;
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||||
sourceTree = "<group>";
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||||
@ -1512,7 +1512,7 @@
|
||||
CLANG_ENABLE_MODULES = YES;
|
||||
CODE_SIGN_ENTITLEMENTS = "SimpleX (iOS).entitlements";
|
||||
CODE_SIGN_STYLE = Automatic;
|
||||
CURRENT_PROJECT_VERSION = 183;
|
||||
CURRENT_PROJECT_VERSION = 184;
|
||||
DEVELOPMENT_TEAM = 5NN7GUYB6T;
|
||||
ENABLE_BITCODE = NO;
|
||||
ENABLE_PREVIEWS = YES;
|
||||
@ -1555,7 +1555,7 @@
|
||||
CLANG_ENABLE_MODULES = YES;
|
||||
CODE_SIGN_ENTITLEMENTS = "SimpleX (iOS).entitlements";
|
||||
CODE_SIGN_STYLE = Automatic;
|
||||
CURRENT_PROJECT_VERSION = 183;
|
||||
CURRENT_PROJECT_VERSION = 184;
|
||||
DEVELOPMENT_TEAM = 5NN7GUYB6T;
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||||
ENABLE_BITCODE = NO;
|
||||
ENABLE_PREVIEWS = YES;
|
||||
@ -1636,7 +1636,7 @@
|
||||
CODE_SIGN_ENTITLEMENTS = "SimpleX NSE/SimpleX NSE.entitlements";
|
||||
CODE_SIGN_IDENTITY = "Apple Development";
|
||||
CODE_SIGN_STYLE = Automatic;
|
||||
CURRENT_PROJECT_VERSION = 183;
|
||||
CURRENT_PROJECT_VERSION = 184;
|
||||
DEVELOPMENT_TEAM = 5NN7GUYB6T;
|
||||
ENABLE_BITCODE = NO;
|
||||
GENERATE_INFOPLIST_FILE = YES;
|
||||
@ -1668,7 +1668,7 @@
|
||||
CODE_SIGN_ENTITLEMENTS = "SimpleX NSE/SimpleX NSE.entitlements";
|
||||
CODE_SIGN_IDENTITY = "Apple Development";
|
||||
CODE_SIGN_STYLE = Automatic;
|
||||
CURRENT_PROJECT_VERSION = 183;
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||||
CURRENT_PROJECT_VERSION = 184;
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||||
DEVELOPMENT_TEAM = 5NN7GUYB6T;
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||||
ENABLE_BITCODE = NO;
|
||||
GENERATE_INFOPLIST_FILE = YES;
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||||
@ -1700,7 +1700,7 @@
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||||
APPLICATION_EXTENSION_API_ONLY = YES;
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||||
CLANG_ENABLE_MODULES = YES;
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CODE_SIGN_STYLE = Automatic;
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CURRENT_PROJECT_VERSION = 183;
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CURRENT_PROJECT_VERSION = 184;
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DEFINES_MODULE = YES;
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DEVELOPMENT_TEAM = 5NN7GUYB6T;
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DYLIB_COMPATIBILITY_VERSION = 1;
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@ -1746,7 +1746,7 @@
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APPLICATION_EXTENSION_API_ONLY = YES;
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CLANG_ENABLE_MODULES = YES;
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CODE_SIGN_STYLE = Automatic;
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CURRENT_PROJECT_VERSION = 183;
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CURRENT_PROJECT_VERSION = 184;
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DEFINES_MODULE = YES;
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DEVELOPMENT_TEAM = 5NN7GUYB6T;
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||||
DYLIB_COMPATIBILITY_VERSION = 1;
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||||
|
||||
@ -2,48 +2,128 @@
|
||||
layout: layouts/article.html
|
||||
title: "SimpleX Chat v5.4 - link mobile and desktop apps via quantum resistant protocol, and much better groups."
|
||||
date: 2023-11-25
|
||||
preview: SimpleX Chat v5.4 - link mobile and desktop apps via quantum resistant protocol, and much better groups.
|
||||
# image: images/20231125-remote-desktop.jpg
|
||||
draft: true
|
||||
imageWide: true
|
||||
permalink: "/blog/20231125-simplex-chat-v5-4-quantum-resistant-mobile-from-desktop-better-groups.html"
|
||||
previewBody: blog_previews/20231125.html
|
||||
image: images/20231125-mobile2.png
|
||||
permalink: "/blog/20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.html"
|
||||
---
|
||||
|
||||
TODO stub for release announcement
|
||||
|
||||
# SimpleX Chat v5.4 - link mobile and desktop apps via quantum resistant protocol, and much better groups.
|
||||
|
||||
**Published:** Nov 25, 2023
|
||||
|
||||
- [Quick start: control SimpleX Chat mobile app from CLI](#⚡️-quick-start-use-profiles-in-SimpleX-Chat-mobile-from-desktop-app)
|
||||
- [What's the problem](#whats-the-problem)
|
||||
- [Why didn't we use some existing solution?](#why-didnt-we-use-some-existing-solution)
|
||||
**What's new in v5.4:**
|
||||
- [Link mobile and desktop apps via secure quantum-resistant protocol](#link-mobile-and-desktop-apps-via-secure-quantum-resistant-protocol).
|
||||
- ⚡️ Quick start - how to use it.
|
||||
- How does it work?
|
||||
- 🤖 Connecting to remote CLI.
|
||||
- [Better groups](#better-groups).
|
||||
- [Faster to join and more reliable](#faster-to-join-with-more-reliable-message-delivery).
|
||||
- [New group features](#new-group-features):
|
||||
- create groups with incognito profile,
|
||||
- block group members to reduce noise,
|
||||
- prohibit files and media in a group.
|
||||
- [Better calls](#better-calls): faster to connect, with screen sharing on desktop.
|
||||
|
||||
## ⚡️ Quick start: use profiles in SimpleX Chat mobile from desktop app
|
||||
There are many [other improvements](#other-improvements) and fixes in this release:
|
||||
- profile names now allow spaces.
|
||||
- when you delete contacts, they are optionally notified.
|
||||
- previously used and your own SimpleX links are recognized by the app.
|
||||
- and more - see the [release notes](https://github.com/simplex-chat/simplex-chat/releases/tag/v5.4.0).
|
||||
|
||||
## What's the problem?
|
||||
## Link mobile and desktop apps via secure quantum-resistant protocol
|
||||
|
||||
Currently you cannot use the same SimpleX Chat profile on mobile and desktop devices. Even though you can use small groups instead of direct conversations as a workaround, it is quite inconvenient – read status and delivery receipts become much less useful.
|
||||
This release allows to use chat profiles you have in mobile app from desktop app.
|
||||
|
||||
So, we need a way to use the same profile on desktop as we use on mobile.
|
||||
This is only possible when both devices are connected to the same local network. To send and receive messages mobile app has to be connected to the Internet.
|
||||
|
||||
If SimpleX Chat profile was stored on the server, the problem would have been simpler - you can just connect to it from another device. But even in this case, accessing the conversation history without compromising the security of double ratchet end-to-end encryption is not really possible.
|
||||
### ⚡️ Quick start - how to use it
|
||||
|
||||
So we decided to implement the solution that is similar to what WhatsApp and WeChat did in early days - allowing a desktop device access profile on mobile via network. Unlike these big apps, we don't use the server to connect to mobile, but instead use the connection over the local network.
|
||||
**On desktop**
|
||||
|
||||
The downside of this approach is that mobile device has to be with you and connected to the same local network (and in case of iOS, the app has to be in the foreground as well). But the upside is that we the connection can be secure, and that you do not have to have a copy of your profiles on the desktop, which usually has lower security.
|
||||
If you don't have desktop app installed yet, [download it](https://simplex.chat/downloads/) and create any chat profile - you don't need to use it, and when you create it there are no server requests sent and no accounts are created. Think about it as about user profile on your computer.
|
||||
|
||||
## Why didn't we use some existing solution?
|
||||
Then in desktop app settings choose *Link a mobile* - it will show a QR code.
|
||||
|
||||
While there are several existing protocols for remote access, all of them are vulnerable to spoofing and man
|
||||
<img src="./images/20231125-desktop1.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-desktop2.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-desktop3.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-desktop4.png" width="510">
|
||||
|
||||
in many cases support of sending files and images is not very good, and sending videos and large files is simply impossible. There are currently these problems:
|
||||
**On mobile**
|
||||
|
||||
- the sender has to be online for file transfer to complete, once it was confirmed by the recipient.
|
||||
- when the file is sent to the group, the sender will have to transfer it separately to each member, creating a lot of traffic.
|
||||
- the file transfer is slow, as it is sent in small chunks - approximately 16kb per message.
|
||||
In mobile app settings choose *Use from desktop*, scan the QR code and verify session code when it appears on both devices - it should be the same. Verifying session code confirms that the devices are connected directly via a secure encrypted connection. There is an option to verify this code on subsequent connections too, but by default it is only required once.
|
||||
|
||||
As a result, we limited the supported size of files in the app to 8mb. Even for supported files, it is quite inefficient for sending any files to large groups.
|
||||
<img src="./images/20231125-mobile1.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-mobile1a.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-mobile2.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-mobile3.png" width="170"> <img src="./images/arrow.png" width="24"> <img src="./images/20231125-mobile4.png" width="170">
|
||||
|
||||
The devices are now paired, and you can continue using all mobile profiles from desktop.
|
||||
|
||||
If it is an Android app, you can move the app to background, but iOS app has to remain open. In both cases, while you are using mobile profiles from desktop, you won't be able to use mobile app.
|
||||
|
||||
The subsequent connections happen much faster - by default, the desktop app broadcasts its session address to the network, in encrypted form, and mobile app connects to it once you choose *Use from desktop* in mobile app settings.
|
||||
|
||||
### How does it work?
|
||||
|
||||
The way we designed this solution avoided any security compromises, and the end-to-end encryption remained as secure as it was - it uses [double-ratchet algorithm](../docs/GLOSSARY.md#double-ratchet-algorithm), with [perfect forward secrecy](../docs/GLOSSARY.md#forward-secrecy), [post-compromise security](../docs/GLOSSARY.md#post-compromise-security) and deniability.
|
||||
|
||||
This solution is similar to WhatsApp and WeChat. But unlike these apps, no server is involved in the connection between mobile and desktop. The connection itself uses a new SimpleX Remote Control Protocol (XRCP) based on secure TLS 1.3 and additional quantum-resistant encryption inside TLS. You can read XRCP protocol specification and threat model in [this document](https://github.com/simplex-chat/simplexmq/blob/master/rfcs/2023-10-25-remote-control.md). We will soon be [augmenting double ratchet](https://github.com/simplex-chat/simplex-chat/blob/master/docs/rfcs/2023-09-30-pq-double-ratchet.md) to be resistant to quantum computers as well.
|
||||
|
||||
The downside of this approach is that mobile device has to be connected to the same local network as desktop. But the upside is that the connection is secure, and you do not need to have a copy of all your data on desktop, which usually has lower security than mobile.
|
||||
|
||||
Please note, that the files you send, save or play from desktop app, and also images you view are automatically saved on your desktop device (encrypted by default except videos). To remove all these files you can unlink the paired mobile device from the desktop app settings – there will be an option soon allowing to remove the files without unlinking the mobile.
|
||||
|
||||
### 🤖 Connecting to remote SimpleX CLI
|
||||
|
||||
*Warning*: this section is for technically advanced users!
|
||||
|
||||
If you run SimpleX CLI on a computer in another network - e.g., in the cloud VM or on a Raspberry Pi at home while you are at work, you can also use if from desktop via SSH tunnel. Below assumes that you have remote machine connected via SSH and CLI running there - you can use `tmux` for it to keep running when you are not connected via ssh.
|
||||
|
||||
Follow these steps to use remote CLI from desktop app:
|
||||
1. On the remote machine add the IP address of your desktop to the firewall rules, so that when CLI tries to connect to this address, it connects to `localhost` instead: `iptables -t nat -A OUTPUT -p all -d 192.168.1.100 -j DNAT --to-destination 127.0.0.1` (replace `192.168.1.100` with the actual address of your desktop, and make sure it is not needed for something else on your remote machine).
|
||||
2. Also on the remote machine, run Simplex CLI with the option `--device-name 'SimpleX CLI'`, or any other name you like. You can also use the command `/set device name <name>` to set it for the CLI.
|
||||
3. Choose *Link a mobile* in desktop app settings, note the port it shows under the QR code, and click "Share link".
|
||||
4. Run ssh port forwarding on desktop computer to let your remote machine connect to desktop app: `ssh -R 12345:127.0.0.1:12345 -N user@example.com` where `12345` is the port on which desktop app is listening for the connections from step 3, `example.com` is the hostname or IP address of your remote machine, and `user` is some username on remote machine. You can run port forwarding in the background by adding `-f` option.
|
||||
5. On the remote machine, run CLI command `/connect remote ctrl <link>`, where `<link>` is the desktop session address copied in step 3. You should run this command within 1 minute from choosing *Link a mobile*.
|
||||
6. If the connection is successful, the CLI will ask you to verify the session code (you need to copy and paste the command) with the one shown in desktop app. Once you use `/verify remote ctrl <code>` command, CLI can be used from desktop app.
|
||||
7. To stop remote session use `/stop remote ctrl` command.
|
||||
|
||||
## Better groups
|
||||
|
||||
### Faster to join, with more reliable message delivery
|
||||
|
||||
We improved the protocols for groups, by making joining groups much faster, and also by adding message forwarding. Previously, the problem was that until a new member connects directly with each existing group member, they did not see each other messages in the group. The problem is explained in detail in [this video](https://www.youtube.com/watch?v=7yjQFmhAftE&t=1104s) at 18:23.
|
||||
|
||||
With v5.4, the admin who added members to the group forwards messages to and from the new members until they connect to the existing members. So you should no longer miss any messages and be surprised with replies to messages you have never seen once you and new group members upgrade.
|
||||
|
||||
### New group features
|
||||
|
||||
<img src="./images/20231125-group1.png" width="220" class="float-to-left"> <img src="./images/20231125-block.png" width="220" class="float-to-left">
|
||||
|
||||
**Create groups with incognito profile**
|
||||
|
||||
Previously, you could only create groups with your main profile. This version allows creating groups with incognito profile directly. You will not be able to add your contacts, they can only join via group link.
|
||||
|
||||
**Block group members to reduce noise**
|
||||
|
||||
You now can block messages from group members that send too many messages, or the messages you don't won't to see. Blocked members won't know that you blocked their messages. When they send messages they will appear in the conversation as one line, showing how many messages were blocked. You can reveal them, or delete all sequential blocked messages at once.
|
||||
|
||||
**Prohibit files and media in a group**
|
||||
|
||||
Group owners now have an option to prohibit sending files and media. This can be useful if you don't won't any images shared, and only want to allow text messages.
|
||||
|
||||
## Better calls
|
||||
|
||||
Calls in SimpleX Chat still require a lot of work to become stable, but this version improved the speed of connecting calls, and they should work for more users.
|
||||
|
||||
We also added screen sharing in video calls to desktop app.
|
||||
|
||||
## Other improvements
|
||||
|
||||
This version also has many small and large improvements to make the app more usable and reliable.
|
||||
|
||||
The new users and group profiles now allow spaces in the names, to make them more readable. To message these contacts in CLI you need to use quotes, for example, `@'John Doe' Hello!`.
|
||||
|
||||
When you delete contacts, you can notify them - to let them know they can't message you.
|
||||
|
||||
When you try to connect to the same contact or join the same group, or connect via your own link, the app will recognize it and warn you, or simply open the correct conversation.
|
||||
|
||||
You can find the full list of fixed bugs and small improvements in the [release notes](https://github.com/simplex-chat/simplex-chat/releases/tag/v5.4.0).
|
||||
|
||||
## SimpleX platform
|
||||
|
||||
|
||||
@ -1,5 +1,27 @@
|
||||
# Blog
|
||||
|
||||
Nov 25, 2023 [SimpleX Chat v5.4 released](./20231125-simplex-chat-v5-4-link-mobile-desktop-quantum-resistant-better-groups.md)
|
||||
|
||||
- Link mobile and desktop apps via secure quantum-resistant protocol. 🔗
|
||||
- Better groups:
|
||||
- faster to join and more reliable.
|
||||
- create groups with incognito profile.
|
||||
- block group members to reduce noise.
|
||||
- prohibit files and media in a group.
|
||||
- Better calls: faster to connect, with screen sharing on desktop.
|
||||
- Many other improvements.
|
||||
|
||||
---
|
||||
|
||||
Sep 25, 2023 [SimpleX Chat v5.3 released](./20230925-simplex-chat-v5-3-desktop-app-local-file-encryption-directory-service.md)
|
||||
|
||||
- new desktop app! 💻
|
||||
- directory service and other group improvements.
|
||||
- encrypted local files and media with forward secrecy.
|
||||
- simplified incognito mode.
|
||||
|
||||
---
|
||||
|
||||
July 22, 2023 [SimpleX Chat v5.2 released](./20230722-simplex-chat-v5-2-message-delivery-receipts.md)
|
||||
|
||||
**What's new in v5.2:**
|
||||
|
||||
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@ -1,13 +1,13 @@
|
||||
---
|
||||
title: Download SimpleX apps
|
||||
permalink: /downloads/index.html
|
||||
revision: 01.10.2023
|
||||
revision: 25.11.2023
|
||||
---
|
||||
|
||||
| Updated 01.10.2023 | Languages: EN |
|
||||
| Updated 25.11.2023 | Languages: EN |
|
||||
# Download SimpleX apps
|
||||
|
||||
The latest stable version is v5.3.2.
|
||||
The latest stable version is v5.4.0.
|
||||
|
||||
You can get the latest beta releases from [GitHub](https://github.com/simplex-chat/simplex-chat/releases).
|
||||
|
||||
@ -21,24 +21,24 @@ You can get the latest beta releases from [GitHub](https://github.com/simplex-ch
|
||||
|
||||
Using the same profile as on mobile device is not yet supported – you need to create a separate profile to use desktop apps.
|
||||
|
||||
**Linux**: [AppImage](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-desktop-x86_64.AppImage) (most Linux distros), [Ubuntu 20.04](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-desktop-ubuntu-20_04-x86_64.deb) (and Debian-based distros), [Ubuntu 22.04](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-desktop-ubuntu-22_04-x86_64.deb).
|
||||
**Linux**: [AppImage](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-desktop-x86_64.AppImage) (most Linux distros), [Ubuntu 20.04](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-desktop-ubuntu-20_04-x86_64.deb) (and Debian-based distros), [Ubuntu 22.04](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-desktop-ubuntu-22_04-x86_64.deb).
|
||||
|
||||
**Mac**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-desktop-macos-x86_64.dmg) (Intel), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.1/simplex-desktop-macos-aarch64.dmg) (Apple Silicon).
|
||||
**Mac**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-desktop-macos-x86_64.dmg) (Intel), [aarch64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-desktop-macos-aarch64.dmg) (Apple Silicon).
|
||||
|
||||
**Windows**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0-beta.3/simplex-desktop-windows-x86-64.msi) (BETA).
|
||||
**Windows**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-desktop-windows-x86_64.msi).
|
||||
|
||||
## Mobile apps
|
||||
|
||||
**iOS**: [App store](https://apps.apple.com/us/app/simplex-chat/id1605771084), [TestFlight](https://testflight.apple.com/join/DWuT2LQu).
|
||||
|
||||
**Android**: [Play store](https://play.google.com/store/apps/details?id=chat.simplex.app), [F-Droid](https://simplex.chat/fdroid/), [APK aarch64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex.apk), [APK armv7](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-armv7a.apk).
|
||||
**Android**: [Play store](https://play.google.com/store/apps/details?id=chat.simplex.app), [F-Droid](https://simplex.chat/fdroid/), [APK aarch64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex.apk), [APK armv7](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-armv7a.apk).
|
||||
|
||||
## Terminal (console) app
|
||||
|
||||
See [Using terminal app](/docs/CLI.md).
|
||||
|
||||
**Linux**: [Ubuntu 20.04](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-chat-ubuntu-20_04-x86-64), [Ubuntu 22.04](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-chat-ubuntu-22_04-x86-64).
|
||||
**Linux**: [Ubuntu 20.04](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-chat-ubuntu-20_04-x86-64), [Ubuntu 22.04](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-chat-ubuntu-22_04-x86-64).
|
||||
|
||||
**Mac** [x86_64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-chat-macos-x86-64), aarch64 - [compile from source](./CLI.md#).
|
||||
**Mac** [x86_64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-chat-macos-x86-64), aarch64 - [compile from source](./CLI.md#).
|
||||
|
||||
**Windows**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.3.2/simplex-chat-windows-x86-64).
|
||||
**Windows**: [x86_64](https://github.com/simplex-chat/simplex-chat/releases/download/v5.4.0/simplex-chat-windows-x86-64).
|
||||
|
||||
@ -8,7 +8,7 @@ title: App settings
|
||||
To open app settings:
|
||||
|
||||
- Open the app.
|
||||
- Tap on your user profile image in the upper right-hand of the screen.
|
||||
- Tap on your user profile image in the upper left-hand of the screen.
|
||||
- If you have more than one profile, tap the current profile again or choose Settings.
|
||||
|
||||
## Your profile settings
|
||||
|
||||
224
docs/rfcs/2023-09-30-pq-double-ratchet.md
Normal file
224
docs/rfcs/2023-09-30-pq-double-ratchet.md
Normal file
@ -0,0 +1,224 @@
|
||||
# Post-quantum resistant augmented double ratchet algorithm
|
||||
|
||||
- [Overview](#overview)
|
||||
- [Problem](#problem)
|
||||
- [Comparison of the proposed solutions](#comparison-of-the-proposed-solutions)
|
||||
- [PQXDH for post-quantum key agreement](#pqxdh-for-post-quantum-key-agreement) (Signal)
|
||||
- [Hybrid Signal protocol for post-quantum encryption](#hybrid-signal-protocol-for-post-quantum-encryption) (Tutanota)
|
||||
- [Problems with ML-KEM / Kyber](#problems-with-ml-kem--kyber)
|
||||
- [Proposed solution: augmented double ratchet algorithm](#proposed-solution-augmented-double-ratchet-algorithm)
|
||||
- [Double ratchet with encrypted headers augmented with double PQ KEM](#double-ratchet-with-encrypted-headers-augmented-with-double-pq-kem)
|
||||
- [Initialization](#initialization)
|
||||
- [Encrypting messages](#encrypting-messages)
|
||||
- [Decrypting messages](#decrypting-messages)
|
||||
- [Alternative approach: CTIDH](#alternative-approach-ctidh)
|
||||
- [Implementation considerations for SimpleX Chat](#implementation-considerations-for-simplex-chat)
|
||||
- [Summary](#summary)
|
||||
- [Notes](#notes)
|
||||
|
||||
## 1. Overview
|
||||
|
||||
Currently SimpleX Chat uses [double-ratchet with header encryption](https://signal.org/docs/specifications/doubleratchet/#double-ratchet-with-header-encryption) to provide end-to-end encryption to messages and files. This document proposes a way to augment this algorithm with post-quantum key encapsulation mechanism (KEM) to make it resistant to quantum computers.
|
||||
|
||||
This document is purposefully written in an informal style to make it understandable for general audience with some technical, but without mathematical background. It does not compromise on the technical accuracy though.
|
||||
|
||||
## 2. Problem
|
||||
|
||||
It is a reasonable assumption that "record-now-decrypt-later" attacks are ongoing, so the users want to use cryptographic schemes for end-to-end encryption that are augmented with some post-quantum algorithm that is believed to be resistant to quantum computers.
|
||||
|
||||
Double-ratchet algorithm is a state of the art solution for end to end encryption offering a set of qualities that is unmatched by any other algorithm:
|
||||
|
||||
- perfect forward secrecy, i.e. compromise of session or long term keys does not lead to the ability to decrypt any of the past messages.
|
||||
- deniability (also known as repudiation), i.e. the fact that the recipient of the message cannot prove to a third party that the sender actually sent this message [1].
|
||||
- break-in recovery [2] (also know as post-compromise security or future secrecy), i.e. the ability of the end-to-end encryption security to recover from the compromise of the long term keys. This is achieved by generating a new random key pair whenever a new DH key is received (DH ratchet step).
|
||||
|
||||
It is desirable to preserve all these qualities when augmenting the algorithm with a post-quantum algorithm, and having these qualities resistant (or "believed to be" resistant [3]) to both conventional and quantum computers.
|
||||
|
||||
## Comparison of the proposed solutions
|
||||
|
||||
### PQXDH for post-quantum key agreement
|
||||
|
||||
[The solution](https://signal.org/docs/specifications/pqxdh/) recently [introduced by Signal](https://signal.org/blog/pqxdh/) augments the initial key agreement ([X3DH](https://signal.org/docs/specifications/x3dh/)) that is made prior to double ratchet algorithm. This is believed to provide protection from "record-now-decrypt-later" attack, but if the attacker at any point obtains long term keys from any of the devices, the break-in recovery will not be post-quantum resistant, and the attacker would be able to decrypt all the subsequent messages.
|
||||
|
||||
In addition to that, the authentication of parties in the proposed scheme is also not post-quantum resistant, although this is not part of double ratchet algorithm.
|
||||
|
||||
### Hybrid Signal protocol for post-quantum encryption
|
||||
|
||||
[The solution](https://eprint.iacr.org/2021/875.pdf) [proposed by Tutanota](https://tutanota.com/blog/posts/pqmail-update/) aims to preserve the break-in recovery property of double ratchet, but in doing so it:
|
||||
- replaces rather than augments DH key agreement with post-quantum KEM mechanism, making it potentially vulnerable to conventional computers.
|
||||
- adds signature to the DH ratchet step, to compensate for not keeping DH key agreement, but losing the deniability property for some of the messages.
|
||||
|
||||
### Problems with ML-KEM / Kyber
|
||||
|
||||
ML-KEM / Kyber used in both Signal and Tutanota schemes is the chosen algorithm by NIST, but its standardisation process raised some concerns amongst the experts:
|
||||
|
||||
- hashing of random numbers that was present in the original submission was removed from the standardised version of the algorithm. See lines 304-314 in the published spec (https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.203.ipd.pdf) and also the linked discussion on the subject: https://groups.google.com/a/list.nist.gov/g/pqc-forum/c/WFRDl8DqYQ4. This decision polarised the experts, with some of them saying that it effectively created a backdoor.
|
||||
- calculation of security levels of Kyber appears to have been done incorrectly, and overall, the chosen Kyber seems worse than rejected NTRU according to [the analysis by Daniel Bernstein](https://blog.cr.yp.to/20231003-countcorrectly.html).
|
||||
|
||||
## Proposed solution: augmented double ratchet algorithm
|
||||
|
||||
We will augment the double ratchet algorithm with post-quantum KEM mechanism, preserving all properties of the double ratchet algorithm.
|
||||
|
||||
It is possible, because although double ratchet uses DH (which is a non-interactive key exchange [4]), it uses it "interactively", when the new DH keys are generated by both parties in turns. Parties of double-ratchet encrypted communication can run one or two post-quantum key encapsulation mechanisms in parallel with DH key agreement on each DH ratchet step, making break-in recovery of double ratchet algorithm post-quantum resistant (unlike Signal PQXDH scheme), without losing deniability or resistance to conventional computers (unlike Tutanota scheme).
|
||||
|
||||
Specifically, it is proposed to augment [double ratchet with encrypted headers](https://signal.org/docs/specifications/doubleratchet/#double-ratchet-with-header-encryption) with some post-quantum key encapsulation mechanism (KEM) as described below. A possible algorithm for PQ KEM is [NTRU-prime](https://ntruprime.cr.yp.to), that is currently adopted in SSH and has available implementations. It is important though that the proposed scheme can be used with any PQ KEM algorithm.
|
||||
|
||||
The downside of the proposed scheme is its substantial size overhead, as the encapsulation key and/or encapsulated shared secret are added to the header of each message. For the scheme described below, when both the encapsulation key and encapsulated secret are added to each message header, NTRU-prime adds ~2-4kb to each message (depending on the key size and the chosen variant). See [this table](https://ntruprime.cr.yp.to/security.html) for key and ciphertext sizes and the assessment of the security level for various key sizes.
|
||||
|
||||
## Double ratchet with encrypted headers augmented with double PQ KEM
|
||||
|
||||
Algorithm below assumes that in addition to shared secret from the initial key agreement, there will be an encapsulation key available from the party that published its keys (Bob).
|
||||
|
||||
### Initialization
|
||||
|
||||
The double ratchet initialization is defined in pseudocode as follows:
|
||||
|
||||
```
|
||||
// Alice obtained Bob's keys and initializes ratchet first
|
||||
def RatchetInitAlicePQ2HE(state, SK, bob_dh_public_key, shared_hka, shared_nhkb, bob_pq_kem_encapsulation_key):
|
||||
state.DHRs = GENERATE_DH()
|
||||
state.DHRr = bob_dh_public_key
|
||||
// below added for post-quantum KEM
|
||||
state.PQRs = GENERATE_PQKEM()
|
||||
state.PQRr = bob_pq_kem_encapsulation_key
|
||||
state.PQRss = random // shared secret for KEM
|
||||
state.PQRenc_ss = PQKEM-ENC(state.PQRr.encaps, state.PQRss) // encapsulated additional shared secret
|
||||
// above added for KEM
|
||||
// below augments DH key agreement with PQ shared secret
|
||||
state.RK, state.CKs, state.NHKs = KDF_RK_HE(SK, DH(state.DHRs, state.DHRr) || state.PQRss)
|
||||
state.CKr = None
|
||||
state.Ns = 0
|
||||
state.Nr = 0
|
||||
state.PN = 0
|
||||
state.MKSKIPPED = {}
|
||||
state.HKs = shared_hka
|
||||
state.HKr = None
|
||||
state.NHKr = shared_nhkb
|
||||
|
||||
// Bob initializes ratchet second, having received Alice's connection request
|
||||
def RatchetInitBobPQ2HE(state, SK, bob_dh_key_pair, shared_hka, shared_nhkb, bob_pq_kem_key_pair):
|
||||
state.DHRs = bob_dh_key_pair
|
||||
state.DHRr = None
|
||||
// below added for KEM
|
||||
state.PQRs = bob_pq_kem_key_pair
|
||||
state.PQRr = None
|
||||
state.PQRss = None
|
||||
state.PQRenc_ss = None
|
||||
// above added for KEM
|
||||
state.RK = SK
|
||||
state.CKs = None
|
||||
state.CKr = None
|
||||
state.Ns = 0
|
||||
state.Nr = 0
|
||||
state.PN = 0
|
||||
state.MKSKIPPED = {}
|
||||
state.HKs = None
|
||||
state.NHKs = shared_nhkb
|
||||
state.HKr = None
|
||||
state.NHKr = shared_hka
|
||||
```
|
||||
|
||||
`GENERATE_PQKEM` generates decapsulation/encapsulation key pair.
|
||||
|
||||
`PQKEM-ENC` is key encapsulation algorithm.
|
||||
|
||||
Other than commented lines, the above adds parameters `bob_pq_kem_encapsulation_key` and `bob_pq_kem_key_pair` to the ratchet intialization. Otherwise it is identical to the original double ratchet initialization.
|
||||
|
||||
### Encrypting messages
|
||||
|
||||
```
|
||||
def RatchetEncryptPQ2HE(state, plaintext, AD):
|
||||
state.CKs, mk = KDF_CK(state.CKs)
|
||||
// encapsulation key from PQRs and encapsulated shared secret is added to header
|
||||
header = HEADER_PQ2(
|
||||
dh = state.DHRs.public,
|
||||
pn = state.PN,
|
||||
n = state.Ns,
|
||||
encaps = state.PQRs.encaps, // added for KEM #1
|
||||
enc_ss = state.PQRenc_ss // added for KEM #2
|
||||
)
|
||||
enc_header = HENCRYPT(state.HKs, header)
|
||||
state.Ns += 1
|
||||
return enc_header, ENCRYPT(mk, plaintext, CONCAT(AD, enc_header))
|
||||
```
|
||||
|
||||
Other than adding encapsulation key and encapsulated shared secret into the header, the above is identical to the original double ratchet message encryption step.
|
||||
|
||||
As an optimization, to save space, it might be possible to add encapsulation key and encapsulated secret only when they change. The downside of this optimization would be that it will be impossible to decrypt the message when the message that has them is skipped or lost, compromising the ability of double ratchet to manage skipped messages.
|
||||
|
||||
### Decrypting messages
|
||||
|
||||
```
|
||||
def RatchetDecryptPQ2HE(state, enc_header, ciphertext, AD):
|
||||
plaintext = TrySkippedMessageKeysHE(state, enc_header, ciphertext, AD)
|
||||
if plaintext != None:
|
||||
return plaintext
|
||||
header, dh_ratchet = DecryptHeader(state, enc_header) // DecryptHeader is the same as in double ratchet specification
|
||||
if dh_ratchet:
|
||||
SkipMessageKeysHE(state, header.pn) // SkipMessageKeysHE is the same as in double ratchet specification
|
||||
DHRatchetPQ2HE(state, header)
|
||||
SkipMessageKeysHE(state, header.n)
|
||||
state.CKr, mk = KDF_CK(state.CKr)
|
||||
state.Nr += 1
|
||||
return DECRYPT(mk, ciphertext, CONCAT(AD, enc_header))
|
||||
|
||||
def DHRatchetPQ2HE(state, header):
|
||||
state.PN = state.Ns
|
||||
state.Ns = 0
|
||||
state.Nr = 0
|
||||
state.HKs = state.NHKs
|
||||
state.HKr = state.NHKr
|
||||
state.DHRr = header.dh
|
||||
// save new encapsulation key from header
|
||||
state.PQRr = header.encaps
|
||||
// decapsulate shared secret from header - KEM #2
|
||||
ss = PQKEM-DEC(state.PQRs.decaps, header.enc_ss)
|
||||
// use decapsulated shared secret with receiving ratchet
|
||||
state.RK, state.CKr, state.NHKr = KDF_RK_HE(state.RK, DH(state.DHRs, state.DHRr) || ss)
|
||||
state.DHRs = GENERATE_DH()
|
||||
// below is added for KEM
|
||||
state.PQRs = GENERATE_PQKEM() // generate new PQ key pair
|
||||
state.PQRss = random // shared secret for KEM
|
||||
state.PQRenc_ss = PQKEM-ENC(state.PQRr.encaps, state.PQRss) // encapsulated additional shared secret KEM #1
|
||||
// above is added for KEM
|
||||
// use new shared secret with sending ratchet
|
||||
state.RK, state.CKs, state.NHKs = KDF_RK_HE(state.RK, DH(state.DHRs, state.DHRr) || state.PQRss)
|
||||
```
|
||||
|
||||
`PQKEM-DEC` is key decapsulation algorithm.
|
||||
|
||||
`DHRatchetPQ2HE` augments both DH agreements with decapsulated shared secret from the received header and with the new shared secret, respectively. The new shared secret together with the new encapsulation key are saved in the state and will be added to the header in the next sent message.
|
||||
|
||||
Other than augmenting DH key agreements with the shared secrets from KEM, the above is identical to the original double ratchet DH ratchet step.
|
||||
|
||||
It is worth noting that while DH agreements work as ping-pong, when the new received DH key is used for both DH agreements (and only the sent DH key is updated for the second DH key agreement), PQ KEM agreements in the proposed scheme work as a "parallel ping-pong", with two balls in play all the time (two KEM agreements run in parallel).
|
||||
|
||||
## Alternative approach: CTIDH
|
||||
|
||||
Instead of using KEM, we can consider using [CTIDH](https://ctidh.isogeny.org). The advantage is a smaller key size, and also as CTIDH is non-interactive [4], there is no need to run two key agreements in parallel, the PQ keys would simply augment DH keys and would be used in the same way.
|
||||
|
||||
The main downside is the absense of performance-efficient implementation for aarch64 architecture.
|
||||
|
||||
## Implementation considerations for SimpleX Chat
|
||||
|
||||
As SimpleX Chat pads messages to a fixed size, using 16kb transport blocks, the size increase introduced by this scheme will not cause additional traffic in most cases. For large texts it may require additional messages to be sent. Similarly, for media previews it may require either reducing the preview size (and quality) or sending additional messages.
|
||||
|
||||
That might be the primary reason why this scheme was not adopted by Signal, as it would have resulted in substantial traffic growth – to the best of our knowledge, Signal messages are not padded to a fixed size.
|
||||
|
||||
Sharing the initial keys in case of SimpleX Chat it is equivalent to sharing the invitation link. As encapsulation key is large, it may be inconvenient to share it in the link in some contexts.
|
||||
|
||||
It is possible to postpone sharing the encapsulation key until the first message from Alice (confirmation message in SMP protocol), the party sending connection request. The upside here is that the invitation link size would not increase. The downside is that the user profile shared in this confirmation will not be encrypted with PQ-resistant algorithm. To mitigate it, the hadnshake protocol can be modified to postpone sending the user profile until the second message from Alice (HELLO message in SMP protocol).
|
||||
|
||||
## Summary
|
||||
|
||||
If chosen PQ KEM proves secure against quantum computer attacks, then the proposed augmented double ratchet will also be secure against quantum computer attack, including break-in recovery property, while keeping deniability and forward secrecy, because the [same proof](https://eprint.iacr.org/2016/1013.pdf) as for double ratchet algorithm would hold here, provided KEM is secure.
|
||||
|
||||
## Notes
|
||||
|
||||
[1] This is often misunderstood to mean that the recipient cannot prove that the sender sent the message at all, which is incorrect, as the recipient has the proof that either themselves or the sender encrypted the message, and as they know that the recipient themselves did not encrypt it, therefore the sender did. So the communication is secure and authenticated for the parties, without providing a proof to a third party.
|
||||
|
||||
[2] The term "break-in recovery" is used in this document, consistent with the terminology of the double ratchet algorithm specification, and also because it can be used to mean both the quality of being able to recover from the compromise and the actual process used to recover.
|
||||
|
||||
[3] This is important to remember that no existing post-quantum algorithms are proven to be resistant to quantum or even conventional computers, therefore the correct approach is to augment rather than replace existing algorithms with the post-quantum ones.
|
||||
|
||||
[4] Non-interactive key exchange is a type of key agreement that allows both parties to generate key pairs independently, without input from another parties, and then use the public keys from each other to compute the same shared secret.
|
||||
15
website/src/_includes/blog_previews/20231125.html
Normal file
15
website/src/_includes/blog_previews/20231125.html
Normal file
@ -0,0 +1,15 @@
|
||||
<p><strong>v5.4 is released:</strong></p>
|
||||
|
||||
<ul class="mb-[12px]">
|
||||
<li>Link mobile and desktop apps via secure quantum-resistant protocol. 🔗</li>
|
||||
<li><p>Better groups:</p>
|
||||
<ul>
|
||||
<li>faster to join and more reliable.</li>
|
||||
<li>create groups with incognito profile.</li>
|
||||
<li>block group members to reduce noise.</li>
|
||||
<li>prohibit files and media in a group.</li>
|
||||
</ul>
|
||||
</li>
|
||||
<li>Better calls: faster to connect, with screen sharing on desktop.</li>
|
||||
<li>Many other improvements.</li>
|
||||
</ul>
|
||||
Loading…
Reference in New Issue
Block a user