Frequently
Asked
Questions
General
What is Ceno Browser?
Ceno is a mobile web browser based on Mozilla Firefox Components. It is designed for accessing and distributing web content (websites) using a novel approach that relies on BitTorrent – a decentralized file sharing network. Ceno’s advantage comes from side-stepping current Internet censorship methods and allowing people to access and share web information in and across regions where connectivity has been interrupted or compromised and ordinary browsers are unable to fetch the content requested by you, the user.
How does Ceno work?
When a website is accessible from your network (e.g. accessing www.canada.ca from your home internet), Ceno will connect to it like a normal web browser.
When a website is not accessible due to network filtering/censorship, Ceno will attempt to get the content for you. How Ceno attempts to find content depends on whether you have chosen to use Ceno in Public or Personal mode.
In Public mode, Ceno will look into the BitTorrent network to see if another Ceno user has recently shared the requested page. If the service can identify the requested page, it will retrieve that page from another user’s device. If the content is not available, Ceno will contact several Injectors to request that website and have it delivered to you.
In Personal mode, you will only contact the Injectors to have that website fetched and delivered to you. The search will not connect to the BitTorrent network and will not attempt to locate the content on other users’ devices.
The content that Ceno retrieves via Ceno network (in Public mode) is stored on your device and made available for sharing with other Ceno users if they request it.
In Personal mode, your requests are encrypted and the Injectors route your requests and the responses from the origin website, but do not connect to the BitTorrent network, do not attempt to locate the content on other users’ devices and do not share the content you receive with other users.
To ensure that your Ceno client can always contact an Injector, we have also created Bridges. If the Injectors are blocked on your network, the Ceno app will look for available Bridges, who will forward your request to the Injectors. The Ceno network currently features around 6,000 Bridges. Their number is always growing. Learn more.
For a more detailed explanation of how Ceno works, please read the Ouinet whitepaper.
Whats the difference between Personal and Public tabs, again?
Public tabs use all connectivity methods available in the Ceno network to get the content you request. When browsing using a Public tab you will leave a record of your activity on the public BitTorrent network (your IP address and website you requested). Content that has been retrieved by your device inside a Public tab will be shared with other Ceno users via the BitTorrent network.
Information requested and retrieved in a Personal tab is not shared with anyone else. No record of your activity is recorded on BitTorrent. Use Personal tabs for logging into social media and other accounts. Also use them if you do not want to be associated on BitTorrent with any of your browsing activity in Ceno.
What are the advantages of using Ceno?
Whether you are living in a part of the world that restricts access to content, or in a remote area with limited access to the internet, through its peer to peer network, Ceno allows you to access information that may otherwise be unavailable.
By allowing users to enable sharing of content they have recently retrieved, Ceno expands access to the internet more generally.
Ceno is free and open source software. It does not track your online activities, it does not bombard you with ads, does not collect your private data and does not sell any data to third parties. In addition, Ceno also offers these advantages:
- Familiar usage: Accessing web content using Ceno Browser feels just like surfing the web on other browsers,
- Faster browsing: Since your Ceno app can retrieve parts of the same content from different members of the Ceno network at the same time, the load of delivering the content is distributed among different devices. This is useful for users as it offers them faster browsing experience, but also for web content publishers as it allows them to avoid resource usage spikes at origin servers.
- Cheaper browsing: Content popular in a particular region tends to get stored on devices in that region, even if the origin server is abroad. If you are interested in that content, your client may get it from some other client in your region, or devices that are on the same local network . In some countries where international traffic is more expensive than local (e.g. in the presence of a national intranet), this can actually save you money.
Ceno’s advantage is evident in a network that filters or blocks websites, or where the network is weak or unstable. In these circumstances, the Ceno app is able to leverage additional methods to retrieve content and deliver it to your device.
Ceno – and all accompanying components of the tool that together create a decentralized network of peers and nodes – is free and open source software. You can inspect our code or re-create the entire network yourself!
What are the risks of using Ceno?
Risks for users
Every technology that deals with sensitive use cases has its advantages and risks.
Leaving trace in public BitTorrent network
By design, Ceno is using the public BitTorrent network for much of its routing and data storage needs. Whenever you request or share a piece of content on the BitTorrent network (Public mode) you create a record that associates your IP address with a piece of content that was retrieved from a particular website.
This is a standard practice for most BitTorrent applications and it is that record that helps other Ceno users find your device in the Ceno peer-to-peer network on the internet, and know what content your device is able to share.
But, if a surveillance organization is monitoring the network activity, they will also be able to see the activity that involves your IP address, although they won’t be able to see the details of the content you have accessed.
Potential higher internet data consumption
Sharing retrieved content with other members of Ceno network uses some data, so users with metered internet connection need to monitor the amount of data that the device running their Ceno app consumes.
In response to these risks, we created a Personal mode for Ceno users where the service does not interact with the BitTorrent network. We recommend this mode for users who do not want any record of their activity to appear on BitTorrent, as well for website operations that require authentication (for example, when logging into your social media accounts).
Your IP address is visible to the Injectors
Injectors can also see requests for content on the network, including the IP address of the user making the request and the name of the website with the desired content.
However, injectors cannot distinguish whether a request came from a Ceno user or a bridge. Thus requests going to the injector cannot be reliably assigned an originating IP addresses.
Injectors are run and managed by the Ceno team. We do not keep any personally identifiable data and we periodically delete all access logs.
Your IP address is visible to Ceno Bridges
To ensure that your Ceno client can always contact an Injector, we have also created Bridges. If the Injectors are blocked on your network, the Ceno app will look for available Bridges, who will forward your request to the Injectors. The Ceno network currently features around 6,000 Bridges. Their number is always growing.
The purpose of Bridges is to act as a ‘middle-man’ between the Ceno app on user’s devices and injectors. All communication that flows through Bridges is encrypted, and Bridges do not have the private keys required to access the content of the communication. Bridges need to know your IP address so they can forward your requests to Injectors and forward the responses they get back to you.
Risks for Bridge operators
Since any user can become a Bridge, do consider the risks that are introduced by this action.
Bridge activity is invisible to the Bridge operator (unless they are actively monitoring their device for incoming and outgoing connections). Their job is to receive network requests from other Ceno users for access to an Injector and forward this request.
Bridge operators will have their device’s IP address listed in the BitTorrent network as an accessible Bridge.
Bridging only works when the network that you are in allows for incoming connections. This is checked automatically by the Ceno client app upon start. Most wireless mobile carriers do not allow for incoming connections.
Learn how to become a Ceno bridge.
Who develops Ceno Browser?
Ceno is a technology created and maintained by the Canadian not-for-profit organization eQualitie. They have incorporated their Ouinet network library into a web browser built from Firefox components for Android and Windows and from WebKit for iOS.
eQualitie has been in existence since 2012, during which time they have been creating and advancing tools to protect freedom of speech, facilitate information exchange, and promote self-expression on the internet.
Some of their other projects include Ouisync, a service for decentralized file sharing; Deflect, a tool for DDoS protection; Baskerville, a machine learning-based attack detection system; and the dComms deployment toolkit for setting up decentralized and federated network services.
What’s the difference between using a VPN and Ceno Browser?
A VPN, or virtual private network, works by creating a secure, encrypted connection between your device and a remote server operated by a VPN provider. This connection masks your IP address and encrypts your internet traffic, helping to protect your online privacy.
VPNs can see who their clients are and what websites they are requesting, which means that level of trust in the VPN operator is required. This is similar to the trust that is required in eQualitie, who operates the Ceno infrastructure.
While VPNs are focused on privacy, Ceno browser focuses on improving deliverability of content that may not otherwise be readily available, by leveraging peer-to-peer technology. The main differences are:
Efficiency: Unlike VPNs, which route all your traffic through a third country, impacting connection speed, Ceno only redirects traffic for blocked sites. This means that non-blocked sites open directly, resulting in faster and more reliable access.
Private data: With VPN services, you often don’t know who is behind them. Since all your traffic passes through a VPN, it can potentially be monitored and analyzed. Many free VPN services engage in selling aggregated user data. Ceno, on the other hand, does not share your information with third parties and does not engage in commercial analytics.
Reliability: VPN services frequently face disruptions, with popular protocols like OpenVPN or WireGuard being blocked. Ceno, which doesn’t rely on proprietary protocols, operates without interruption. Additionally, Ceno is free to use and does not require any fees.
What’s the difference between using the Tor and Ceno browsers?
Tor works by routing your internet traffic through a series of volunteer-operated servers, known as Onion routers, which encrypt your data at each step. This process, called Onion routing, makes it difficult for anyone to trace your online activity back to your original IP address, providing a high level of anonymity. Using Tor makes it more difficult to trace a user’s Internet activity by preventing any single point on the Internet from being able to view both where traffic originated from and where it is ultimately going to at the same time.
Tor is an excellent option for privacy from Internet surveillance and website operators. If it works in your network environment, we recommend it, provided that you’ve also read their support documentation
Unlike Tor Browser, Ceno Browser is not a tool for anonymity because it uses publicly available peer-to-peer infrastructure (BitTorrent), that can be queried for IP addresses that it contains. The focus of Ceno Browser is on caching the website content that may not otherwise be easily reachable and sharing it between Ceno users who request it.
Why do you believe Ceno will work during internet blocks or shutdowns?
Ceno is already being used in many countries where the internet has been disconnected or restricted. We know that the users are able to use Ceno, as we receive their feedback via Google Play Store, GitLab and by email, and we also monitor reachability of our injectors which are placed in strategic location to facilitate accessibility to relatively unrestricted internet.
Is Ceno browser free to use?
Yes. Ceno is free to download and use, no payment is necessary.
eQualitie offers Ceno as a free browser to ensure that users have access to a tool that supports their deeply held convictions and values that “promote and defend fundamental freedoms and human rights, including the free flow of information online”
Is there a Windows or iPhone version?
Ceno is available for Windows and iOS users. Find links to these releases on the Download page. Note that it is possible to install and run the iOS version on Mac and iPad devices as well.
Is there an F-Droid version?
We previously maintained an F-Droid release of Ceno. However, due to the complex and time-consuming build process required for publishing to F-Droid’s official repository, we do not currently maintain an F-Droid release. The Ceno for Android code is entirely open source and freely available under the MPL 2.0 license, you may build it yourself by following the instructions in GitLab.
Usage
Can others find my IP address?
If you opt-in to being a Bridge, yes, your IP address will be visible to any other Ceno user, see the risks to Bridge operators section above for more information.
Additionally, if you browse sites in Public mode, your IP address will be associated with content you have fetched via the Injectors.
If you opt-out of being a Bridge and only use Ceno in Personal browsing mode, only the Injectors will see your public IP address.
When I operate a Ceno bridge – is it possible that I am helping someone to access content which is illegal in my country?
Yes. However, bridges only relay encrypted communication between a Ceno app and an injector. This means that a bridge shall never make direct requests for content to any other server on someone else’s behalf and it is not able to access or read requests that it routes on behalf of other Ceno network participants.
Can Ceno help me access the blocked websites?
Short answer: yes, it finds a roundabout way to make them available to you.
Blocked websites are usually blocked in one specific region, and not worldwide. Ceno doesn’t ‘unblock’ those websites, as such, but finds a roundabout way of accessing them from countries or regions with less restricted internet access. Ceno network then mirrors them and makes those mirrored sites available to Ceno users.
Example:
Imagine the site bbc.com is blocked in your region. When you try to open “bbc.com” by simply typing this address into your normal browser’s address bar, the response will be a “site blocked” page. But if you type it in the Ceno’s address bar, your Ceno app will detect that the website is not accessible and it will send a request through a proxy server, it (not you) will open the BBC website and send you the content of its main page.
Ceno Browser uses trusted proxy servers, known as Injectors, to deliver the desired content when it is not readily available by accessing the origin website directly.
For some popular websites, eQualitie crawls them on a server in Canada, makes cache bundles from them, and then syncs those cache bundles with servers in restricted areas – which makes that content reachable from those regions even when it cannot otherwise be reached.
The restricted content can be accessed either by servers (operated by eQualitie) as described above, or by individual devices that belong to Ceno users via P2P Bittorrent protocol.
The principle is the same: for users who are able to access the content, the Ceno app will cache that content, and make it available via peer-to-peer network to other Ceno users who request it.
List of regularly crawled website is available here. If you would like us to add specific websites to this list, please contact us at support [at] ceno [dot] app or via our social media.
Who is Ceno for?
Ceno is meant for everyone but is particularly convenient for people interested in Web content that is blocked or filtered on their network, and those living in countries where connectivity to the global Internet is spotty, unreliable or expensive. It encourages and enables the sharing of web content among users, creating a decentralized network of peers helping each other.
Warning: Ceno is not an anonymity tool. In fact, using Ceno may allow others to know whether you have accessed or are sharing certain Web content. Please take careful consideration of which risks you can assume by using this tool. See risks for further information.
Can Ceno Browser replace my current browser (Chrome/Firefox/Safari)?
Short answer: yes.
Since Ceno is based on Mozilla Firefox , it provides all the features that are expected from a modern browser.
Ceno can be used in Public or Personal browsing mode.
Please read the section on risks for more information.
Can I use Ceno Browser to access Twitter, Facebook and Gmail?
Short answer: yes, by using personal browsing mode.
Do I need to be connected to Wi-Fi to use Ceno Browser?
Short answer: no, but we strongly recommend it.
Although Ceno should work fine on a mobile connection, there are two reasons why we recommend using a Wi-Fi connection instead:
- Ceno consumes an extra amount of data which may result in a higher phone bill . or exhaust your data allocation if you have a metered internet connection.
- Mobile connections often make reaching your device more difficult from the outside than Wi-Fi ones, thus decreasing the chances that you can help other users get content.
Privacy and security
Will my device store content that I did not request?
Short answer: no.
Ceno only stores content that you requested (using public browsing) and will share it with other Ceno users if they request it.
For your security, we recommend you avoid visiting suspicious sites, just like when you use other browsers.
What data is seeded from my device?
Your Ceno app seeds the content requested by you and retrieved over Ceno public network. To see the websites that your Ceno app can share with other peers in the Ceno network, you can go to Settings > Data > Shared by you. In the Settings > Data > Local cache you can see the amount of data that is stored in the cache of your Ceno app.
If you do not wish to continue sharing this data with peers in the Ceno network, you can easily delete it by going to Settings > Data > Clear cached data
Can anyone else find out what I seed?
Potentially yes. There are companies and organizations dedicated to internet surveillance,. Peer-to-peer applications are often monitored for copyright infringements on behalf of copyright holders. As stated before, Ceno is not an anonymity tool, but a tool that aims to improve users’ ability to reach content that they wouldn’t otherwise be able to reach. This could be due to poor connectivity in their region, due to ISP blocking certain sites or other reasons.
Can anyone see if I am using Ceno Browser to access Web sites?
Short answer: yes, with some technical knowledge and resources.
Ceno is not an anonymity tool. An adversary able to spy on your network traffic can see content being requested from or served to another user from your device. The adversary can also assess whether you are sharing a particular website, although they cannot list all the content that you are sharing.
However, content being retrieved into the network directly from the origin websites or using Personal browsing will travel over encrypted connections.
Can my private data leak to the distributed cache?
In Public browsing mode, Ceno removes all potentially private data (passwords, cookies, GET parameters) from any request for content. When the content comes back to the client on your device, it is further analyzed, and if the origin server indicated that the content may be private or contain private data, Ceno will not share it with other participants in the Ceno network.
In personal browsing mode, all communication between your client, injectors and origin servers is encrypted, and nothing is cached for peer-to-peer sharing, so no personal data can be exposed to it.
Can the origin server know whether I am using Ceno?
When your Ceno app uses an injector to get some content from its origin server, there may be a way to mark your request as coming from Ouinet, but this does not link it to you or your particular device. However, if your request did contain some personally identifiable information, it could be used to mark you as a Ceno user.
In general, if a particular website (such as a governmental site, insurance company or maybe a hospital) expects you to connect to it as an identifiable individual, from a specific region (or from a national intranet), we recommend that you use a normal Web browser instead of Ceno.
Can Ceno Browser developers monitor me?
Due to the public nature of the BitTorrent protocol, developers can see which websites Ceno users have requested. eQualitie, the company behind the development of Ceno Browser, collects some anonymized usage metrics from the application, but does not share any personally identifiable information with third parties. See the metrics documentation for more detailed explanation of what is collected. Users may opt-out of the metrics collection at any time via Settings > Background Metrics > Ceno Metrics.
Can authorities monitor me?
This is extremely difficult — but possible. In this case, they will only know the IP addresses of the users and a list of sites that one of the browser users has visited at least once. To emphasize: Ceno is a tool for accessing websites, not for providing anonymity. If anonymity is what you need, you can use other tools: VPNs or Tor Browser. In a shutdown scenario, these solutions may not work, however they are effective in regular situations.
Will other users access the internet through my phone?
By default, no. Other users can only receive cached copies of the pages you have opened.
If you configure your Ceno app as a Bridge, then that Bridge may be used by other users who are otherwise unable to access the desired content.
Here is the relevant section of the technical guide: Bridging in Ceno.
Does Ceno steal passwords?
No.
If you want to verify this, you can review the browser’s open source code here: Ceno Browser on Gitlab.
Resource usage
Does Ceno Browser use a lot of data?
Short answer: more than your usual browser.
Whenever your Ceno Browser serves content to another user or forwards their traffic, it is consuming extra data depending on factors like how popular or large the content is, and how well-connected your device is.
Although Ceno is much lighter in resources than other data-sharing applications, it can still result in increased data usage and fees. We recommend keeping an eye on the app’s mobile data usage under Android settings, as well as on your metered internet connection at home.
To minimize the risks of elevated bills, ideally the peers who share the content would be on the same Wi Fi network so sharing can occur within that local network.
Does Ceno Browser use a lot of battery on my device?
Short answer: more than your usual browser.
Ceno uses various techniques for serving content to and forwarding traffic for other users. This consumes extra battery power. Also, for optimal performance of the whole Ceno network, even when your device is not actively helping other users, it needs to keep running in the background. This consumes a small amount of battery power, which can vary between different devices.
If you need to save battery, you can go to Ceno > Settings > Permissions and enable the setting Battery Optimisations if it was disabled. Alternatively, you can temporarily stop the Ceno app.
Troubleshooting
I cannot open any web pages, what can I check?
The first thing to check is the state of your internet connection. Are you able to open any webpages using other browsers (Firefox, Chromium)? If yes, then…
Please check the status of Ceno Browser Service in the Settings > About section. It should read: Started. If it does not disaply that status, please try restarting your Ceno app. If after the restart, the state of the Ceno Browser Service is Started, you should be able to access some webpages. But if it is still not Started, then there may be other problems in your network.
If your internet connection is working correctly, but the Ceno Browser Service still does not show Started, or if it does show Started but you are still not able to retrieve any pages, please contact us at support [at] ceno [dot] app.
As we have seen before, to retrieve webapges, Ceno browser needs to access the BitTorrent P2P network. One possible reason for not being able to get into BitTorrent (more so when you run Ceno for the first time), is that the default bootstrap servers used by the Ceno network are blocked or unreachable. In that case you may want to try providing Ceno with extra BitTorrent bootstrap servers in the Settings > Developer tools > Network details > BitTorrent bootstraps. You can ask us if you do not know of any such server. After setting the extra bootstraps, please restart the application. If the problem persists, contact us at support [at] ceno [dot] app.
Accessing some content shows “Failed to retrieve the resource”- what to check
When you see this message, it means that Ceno tried all available mechanisms to access the content, but none of them succeeded.
Please make sure that the following requirements are fulfilled for Ceno to work:
- You are running a recent version of Ceno browser. Obsolete versions may not be able to communicate with newer injectors or other clients. You can get the up to date versions here.
- All access mechanisms in the Settings > Developer Tools > Website sources screen are checked. Otherwise Ceno will not be able to circumvent some connectivity issues when accessing content.
- Ceno Broser Service status is Started
- Your device has a working connection to the network, i.e. your normal Web browser is able to open some Web sites. Ceno cannot work when all network connectivity is shut down (although users may still find a common Wi-Fi access point to do device-to-device sharing).
A page shows bogus content (like a block message)
This may happen when you used an old version of Ceno to visit a blocked site in the past. Ceno then remembered that, and now automatically tried to open the blocked site again.
One way to fix this issue is to clear Ceno’s normal browsing cache by choosing Settings> Data > Clear cached content.
Others cannot retrieve content seeded by my device
- First, make sure that your device is still seeding the content by going to the Ceno Settings > Developer tools > Website sources page, and uncheck all website sources other than Shared by other Ceno users. Then try to access the content that should seed from your device to your peers: on your device this content should load (at least partially). Tapping on the Ceno button at the address bar should open the information screen that shows that the contents you just viewed was From Ceno cache. From Ceno cache should have a value greater than zero next to it, and all other options should have value 0 (because on this occasion this content was loaded form your own device and not from Ceno network).
- If the content loads correctly on your device, it means that the content is in your cache and your peers should be able to source it from your device.
- If the content does not load, it could be that Ceno has already removed it, since it automatically cleans up stale content (older than a week by default) from your local cache.
- To load it again into your cache, please go to Settings > Developer tools > Website sources and check the Ceno network (public), then access the desired website. If you’re able to access it, it will be cached on your device.
- Please allow a couple of minutes to pass for the device to announce the content in the distributed cache index so that your peers’ devices are able to discover it.
- Make Shared by other Ceno users the only checked box again and access the content once more; if it still does not load, it may be that the particular content is not deemed safe for sharing by the Ceno app.
- If the previous step works, but another device with only the Shared by other Ceno users source enabled still shows “Failed to retrieve the resource…”, there are two possible scenarios.
- If both devices are in the same network (e.g. on the same Wi-Fi access point), it could be that the network does not allow direct communication between devices connected to it. This happens in some public Wi-Fi networks, so try using a private one.
- If the devices are in different networks, it could be due to a variety of reasons. One of them is that the network of the first device does not allow incoming connections: if you open its Ceno Settings > Developer tools > Network details page, under Reachability status it should say reachable or likely reachable. Otherwise seeding may not be possible from that network as it is.
Technical note: If your device reports undecided reachability and you can change the configuration of the access point, you may create a permanent port forwarding rule towards your client. See here for further instructions.
Glossary
Peer-to-Peer (P2P)
Peer-to-peer (P2P) means that computers or smartphones connect directly to each other for data transfer, rather than to a central server. . In such a network, all participants have equal privileges and capabilities. Ceno uses the P2P BitTorrent protocol for website access and service discovery, allowing users to obtain copies of web pages not only from the website itself but also from other users.
BitTorrent
BitTorrent: is a communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a decentralized manner. Many people use this protocol for downloading music and movies from others via torrents.
Bridges
Run by Ceno users who opt-in to become a Bridge, and by eQualitie. Bridges connect Ceno users to Injectors – when these are otherwise unavailable to them
Injectors
Run by eQualitie. Injectors receive requests from Ceno users for website pages, fetch them from the source, then break them down into individual files, signing each one of them cryptographicaly. Finally Injectors return the requested content to the user.
Seeders
Clients offering some particular content over the distributed cache are said to be seeding it or to be their seeders (these terms come from the P2P file-sharing world).
