Ring Sessions: Monero-Inspired Privacy for Your Connections

The headline feature of this release is Ring Sessions, a new opt-in privacy enhancement available to plan subscribers that draws direct inspiration from Monero’s legendary ring signature technology. This feature fundamentally changes how your VPN sessions appear on the Sentinel blockchain, making it harder for observers to extract meaningful metadata about your activity.

When you connect to a node through Meile dVPN, your wallet creates a unique session transaction that gets recorded on-chain. This transaction inherently contains metadata, including the timestamp of your connection and which specific node you’re connecting to. For privacy conscious users, this on-chain footprint has been a point of concern.

Ring Sessions addresses this by generating 8 decoy session transactions simultaneously with your real connection. These decoys select random nodes from your plan and create legitimate looking session transactions that blend together with your actual session. The result is that any observer attempting to analyze blockchain data sees 9 nearly identical transactions occurring at the same time, with no way to distinguish which one represents your true connection. Your real session effectively hides in plain sight among the decoys, obfuscating the metadata that would otherwise reveal your VPN usage patterns.

This feature is currently opt-in and can be enabled through the Settings menu. The initial implementation uses 8 decoys, a number carefully chosen to provide meaningful privacy benefits without significantly impacting connection times. The team has additional improvements planned for future releases, and the feature will continue to evolve.

It’s worth noting that Ring Sessions only became technically possible following the Sentinel v12 network upgrade in October. Prior to this upgrade, wallets were restricted to maintaining only one active session at a time, making the decoy approach impossible. The v12 upgrade lifted this restriction, opening the door for this innovative privacy enhancement.

Zephyr Protocol and ZSD: Private Stablecoin Payments

Meile dVPN v2.5.0 introduces support for Zephyr Protocol’s ZSD stablecoin as a payment option for plan subscriptions, marking the integration of another privacy-focused cryptocurrency and notably the second private stablecoin to be supported by the application.

Zephyr Protocol represents one of the most innovative developments in privacy-preserving decentralized finance. Built as a fork of Monero, Zephyr inherits the battle-tested privacy technology that has made Monero the gold standard for confidential transactions. All transactions on Zephyr utilize ring signatures, stealth addresses, and RingCT (Ring Confidential Transactions), ensuring that senders, receivers, and amounts remain private by default.

What makes Zephyr truly groundbreaking is its implementation of the DJED algorithmic stablecoin protocol. DJED was originally conceived by IOG (Input Output Global), the company behind Cardano, with the protocol designed by Charles Hoskinson’s team. The DJED design creates a crypto-backed stablecoin that maintains its peg through an innovative reserve mechanism and mathematical guarantees rather than centralized collateral or pure algorithmic rebasing.

Zephyr’s implementation brings DJED into the privacy coin space, creating ZSD (Zephyr Stable Dollars), a stablecoin that combines price stability with Monero-grade privacy. This means Meile dVPN users can now pay for their subscriptions with a stable-value asset while maintaining complete transaction privacy. Neither the amount paid nor the parties involved in the transaction are visible on the blockchain, providing an unprecedented level of financial privacy for VPN services.
https://zephyrprotocol.com/

Auto-Filtering of Plan Nodes

User experience receives a meaningful upgrade in v2.5.0 with the introduction of automatic node filtering for plans. Previously, users needed to manually click the “Filter Nodes” button after expanding their plan to see which nodes were available and connectable. This extra step, while minor, added friction to the connection process.

Now, simply expanding a plan automatically filters the node list to display only the nodes included in that plan that are currently online and ready to accept connections. This streamlined workflow reduces the clicks needed to get connected and provides instant visibility into your available options. It’s a small change that makes the daily experience of using Meile dVPN noticeably smoother.

Firo InstantLock: Lightning-Fast Private Payments

Building on our commitment to supporting privacy-preserving payment methods, v2.5.0 integrates Firo’s InstantLock technology for Spark transactions. This feature enables near-instant settlement of private payments, dramatically reducing the time users need to wait for their subscription transactions to confirm.

Firo’s InstantLock technology has its roots in Dash’s InstantSend (originally called InstantPay), which pioneered the concept of using masternode quorums to lock transactions and provide immediate finality. When a Firo transaction is sent with InstantLock, a quorum of masternodes reaches consensus on the transaction within seconds, allowing merchants and services to accept the payment with confidence before it’s included in a block.

The practical impact for Meile dVPN users is substantial. Transactions can now be confirmed as quickly as Bitcoin Lightning payments, meaning you can complete your subscription purchase and start using your VPN almost immediately. Combined with Firo’s Spark protocol, which provides strong privacy guarantees for your payment, InstantLock delivers the best of both worlds: privacy and speed.
https://firo.org

Slimmed-Down SDK: Faster Boot Times Return to Windows

Under the hood, v2.5.0 delivers a significant technical improvement that Windows users in particular will appreciate. The development team successfully reduced the size of the sentinel-protobuf SDK dependency from a hefty 34MB down to just 1MB, eliminating substantial bloat that had accumulated in the codebase.

This 97% reduction in SDK size translates directly into improved application performance. Windows users will now experience boot-up times under 10 seconds again, returning to the snappy startup experience that users expect from desktop applications. While this change happens entirely behind the scenes, the impact on daily usability is immediately noticeable.

Meile dVPN v2.5.0 is available now for Windows, macOS, and Linux. Whether you’re drawn to the enhanced on-chain privacy of Ring Sessions, the financial privacy of Zephyr/ZSD payments, the convenience of auto-filtering and InstantLock, or simply the faster boot times, this release has something meaningful for every user. Download the latest version and experience the next evolution of decentralized VPN technology.
https://meile.app

Linkability is real. If you don’t know what it is, or never heard the term before, it refers to the ability by blockchain analysis firms to create weighted links between seemingly random wallets on chain and even between chains. Most of these firms are using AI and timing attacks to distinguish how related two wallets on the same blockchain are. Much of the analysis is also used to establish correlation between wallets on various chains when people use swap protocols or exchanges.

If you bought your coins on a KYC exchange such as KuCoin, you can assume that exchange data is shared with firms like Chainalysis or Ciphertrace. Withdrawing KYC’d coins to your wallet essentially KYC’s that wallet. Any funds you send from that wallet creates a (KYC) link to the receiving wallet. It becomes a web of linkable transactions and individuals.

Linkability is a real threat to user’s privacy especially when paying for dVPN service. Meile has spent over two years developing ways around this by accepting cross-chain payments from privacy coins; but what about when you pay for a Sentinel dVPN plan with your Sentinel wallet in either Meile or Sentinel Shield? Due to the transparent nature of the Sentinel chain, linkability poses a threat to your dVPN usage.

In this article we will discuss methods for eliminating linkability of your Sentinel wallet used to pay for dVPN service. Networks within Cosmos such as Penumbra, Namada, and Secret all aid in this ability to eliminate linkability and preserve your privacy.

Beating linkability in Cosmos with Penumbra

We will focus our attention for the time being on Penumbra. In July 2024, Penumbra (https://penumbra.zone)launched their mainnet and the first block was produced. It was a bold endeavor because Penumbra is only one of a very limited number of blockchains who have fully shielded (zk-SNARKS) transactions with no transparent addresses. The best part of Penumbra is that its home is in the Cosmos Ecosystem giving many users the ability to transact privately between chains.

We chose Penumbra in this article over Namada and Secret because Penumbra offers the best privacy of the three; not to discredit Namda or Secret, which are also viable alternatives to defeating linkability in the Cosmos Ecosystem. Penumbra is still new as it does not yet have large user adoption, limiting the shielded pool (the more users, the larger the anonymity set); but we are certain its supremacy will shine in the coming months and years.

To get started download the Prax Wallet from the Chrome Store

Set it up like any other wallet, then navigate to https://app.penumbra.zone – this is the web interface in which you can process transactions. All ZK proofs and computations are stored locally on your computer for privacy and security purposes. The wallet will begin syncing with the blockchain, which shouldn’t take more than 30 minutes. While it is syncing, create a new wallet in your favorite Sentinel dVPN application. We will be using Sentinel Shield in this tutorial.

Save the seed phrase, and also import it from your dVPN application into Keplr.

Shielding and Unshielding USDC to be used to purchase P2P

Once your Prax wallet has synced, pick up a little bit of $UM on Osmosis and IBC transfer it to your Prax Wallet. We will show how to shield $USDC to Prax, but the process is the same.

With $USDC on an existing Noble wallet in Keplr, open the Penumbra app and click on Shield assets and connect your Keplr wallet to the Penumbra app. Click “Manual Deposit” and select the amount you wish to shield. Please note that you should Shield more than you plan on unshielding. This is to eliminate a link between the same amounts going in and coming out of Penumbra.

Shielding is like a normal IBC transfer except it becomes invisible on the Penumbra blockchain.

Once you’ve shielded your $USDC, wait a day or two before unshielding a portion of it. This is because there is a common threat called a “timing” attack. Which is when assets go into a shielded pool and come out of the pool they can be correlated with how close the timestamps between the transactions are and how similar the quantity of a given asset are [3]. Remember, the longer your coins stay shielded on Penumbra the more privacy they gain. If you are patient and plan far enough in the future, a week or more will give you maximum anonymity. In my case, I always have a stack of coins shielded on Penumbra, so going in and coming out amounts and timestamps are impossible to correlate.

When enough time has passed, open the Sentinel Shield wallet in Keplr that you imported in the previous section. Grab the Noble wallet address and now we’re ready to unshield $USDC to this wallet. Right now, there should be 0 txs on all chains with the Sentinel Shield wallet – it’s a ghost as they say.

Unshield your $USDC by clicking “Withdraw”

I selected $2.00 plus some change for gas fees. This again is similar to a normal IBC transfer to the destination Noble address (where funds are leaving a shielded pool and returning to the native chain). Once you’ve done this, you will have an amount in Noble, which you will want to IBC transfer (in Keplr) to Osmosis.

With the $USDC now on Osmosis you can swap it for $P2P. Then simply use the Osmosis interface to IBC transfer to the Sentinel chain.

If you were patient in shielding and unshielding your $USDC, the $P2P which is now in your dVPN application wallet will be unlinkable to any past history thanks to the Penumbra protocol. Continue using your favorite dVPN application with full privacy!

References:

[1] https://guide.penumbra.zone/

[2] https://docs.sentinel.co

[3] https://www.chainalysis.com/blog/is-bitcoin-traceable/

It is with great pleasure that we announce the DAO extending this service for another year in 2025. Users and developers can use the RPC, API, or gRPC with the following addresses in their applications to gain access to this unique service allowing our Chinese friends unfettered access to the Sentinel blockchain and its services.

Access to China node

RPC:

https://rpc.dvpn.me:443

API:

https://api.dvpn.me:443

gRPC SSL

grpc.dvpn.me:443

gRPC non-SSL

grpc.dvpn.me:9090

Once in a while, Meile may freeze up if left open too long or unexpectedly quit after running for a long time. These things happen with many apps and Meile is no exception. However, if you were connected to a node while this occurs, there may seemingly be no way to disconnect, or possibly you end up with a severed internet connection on your device. Never fear, the way Meile was designed we use external backend scripts to handle the networking on the computer. You can use these scripts in the case of such an occurrence. Here we present how to do this on Apple OS X if this occurs on your device.

Steps to restore your internet on OS X

Open your finder, go to “Applications->Utilities” and open a terminal.

Type the following commands once your terminal opens

cd ~/.meile-gui/bin

This will place you in our scripts folder. Now, there is one of two actions you can take which depends if you were connected to a Wireguard node or a V2Ray node. The first case covers if you were connected to a Wireguard node before your internet connection was severed. Type the following in the terminal for this case:

./sentinel-disconnet.sh

You will be prompted for your administrator password and then the script will close the Wireguard tunnel and restore the WiFi or Ethernet connection as it was before.

In the case of being connected to a V2Ray node before Meile quit or your internet connection was severed; type the following in the terminal

./tun2routes.sh down

Again this will prompt for your administrator password and will force quit the v2ray protocol and the tun2socks routing protocol. It will also restore your network routes to default.

Viola! Your internet connection should be restored on OS X without restarting.

Follow our blog for updates on how to do this on Windows and Linux in the case of the frustrating computer occurences.

UI Revamp

Undertaking a revamp of the user interface is an arduous task with a lot of moving components and changes that have to be just right so the user can expect a good experience.

So far we have most of the commits in place to have Meile’s main screen resemble the picture above. Thanks to the work of Tkd-Alex who has managed to recreate the figma designs.

Tkd-Alex has also managed to recreate a similar design to the figma node screen as seen above. Finally we view the Wallet screen which may change depending on our implementation

We have currently in place in v1.8.0 the carousel that will be used to slide the map over to the node screen. The remaining parts still left to be done is to overlay the bandwidth widgets along with the node information widgets over the bottom of the map.

Subscription Plans

In Meile dVPN v2 we will be featuring subscription plans which can be purchased with various crypto currencies, including but not limited to:

Monero, BTC, BTC Lightning, Stable Coins, DASH, LTC, DOGE, and Pirate Chain.

We have our BTCPay server up and running and test invoices from the Meile backend have been successful for payments with BTC, BTC Lightning and Monero. A prototype of the subscription dialog interface can be seen below.

You will also be able to pay with IBC enabled coins via your wallet.

Meile Cache Server

Because Sentinel now has over 11,000 nodes, the direct blockchain query that we have been using in Meile causes a long delay to show most of the nodes. In many cases not all nodes are found in the direct query due to so many requests having to be sent by the client to find the nodes.

This is where the work on our Meile Cache Server comes in. We have set up a cache server many months ago that fuels our Metabase Analytics software. We have extended this using the Sentinel Python SDK that was developed by MathNodes, Nast0r and Tkd-Alex.

We use the SDK to query the nodes directly and feed it to a database that will provide an API endpoint for Meile to query directly on load for all online nodes. The query runs every 10 minutes and the API is updated every 12. This will give a shot in the arm to the load time and users can expect a load time when launching Meile to be under 15 seconds.

Conclusion

A lot of work has been poured into this release and we expect a final tested version to arrive within the coming weeks (no later than February 29th). We hope it will be received well as much time and effort has been spent getting it right.

The additions of the Meile Subscription Plans will be our second attempt at profit seeking within our whitelabel app. Right now our only profits come from the Meile FIAT Gateway, which will continue to exist in v2.

Subscription plans offer a wide array of possibilities for whitelabel developers, however there is a lot of maintenance surrounding subscription plans that go on in the background.

We are excited to share this post with the community in anticipation for Meile v2.0.0!

Introduction

One of the community members within the Sentinel Network and a code contributor to the MathNodes desktop application, Meile, Tkd-Alex has built a simple and easy to use web interface for hosting a local or remote Sentinel DVPN node.

Install

All the instructions for install are located on the Tkd-Alex’s github (https://github.com/Tkd-Alex/)

We will list the basic steps here for completion:

1. Clone the repository

2. Make sure to have Python >= 3.10 and the virtualenv package installed

3. Install the python requirements

virtualenv -p python3 venv
source venv/bin/activate
pip install -r requirements.txt 

4. Execute the script:

python main.py

5. Create a dashboard settings 6. Navigate to http://127.0.0.1:3845/servers (default one, or you custom `listen_on` and `listen_port` values) and enjoy the dashboard

Features

The basic main screen of Node Spawner presents you with text fields to enter in your hostname, username, and ssh port. If you are installing on a LAN computer enter your 192.169.x.x of the computer hosting the node. Likewise, if you are installing on a VPS purchased through an online provider, enter the credentials in the text fields. Once you add a few servers you will be presented with the following:

Clicking on the right with the squre box with an upward arrow in it, you will then be presented with the install and configuration screen. Here you can install the dvpn-node requirements, the docker image, configure the dvpn node software to your preferences and run the dvpn node.

In this image you can see on the top right the menu to install the dvpn node. Here we are loading a node that already has the software installed.

Furthermore, you can view the configurations and logs of the running dvpn node docker image

It shows the uptime of the node a long with a section for the realtime logs as seen below:

Overview

The Node Spawner by Tkd-Alex is a very handy component for novice users who want to get into the space of earning crypto for providing resources to the Sentinel Network. He has created a very easy install and a simple interface that anyone can use. We highly recommend this for novice and even users running 10-50 nodes, as it will save them a lot of typing and time compared to the tradition SSH maintenance of the nodes.

Right now is the perfect time to begin hosting nodes as Node Revenue (i.e., the DVPN coins a provider receives from subscriptions by users and subscription plans created by White-label app developers like ourselves) is at an All Time High:

You can get the DVPN Node Spawner at Tkd-Alex github page:

https://github.com/Tkd-Alex/dvpn-node-spawner

Today marks the start of a new crowdfunding campaign by MathNodes. We have previously awarded Monero bounties to developers who contribute code to our GitHub codebases. Similarly, we will use this same strategy to gain insight into the Sentinel blockchain with our analytics dashboard, Metabase.

Crypto currencies, especially privacy coins, enable fast, instant, and anonymous transactions and are an ideal way to crowdfund for development of resources on a global scale. Crypto currency was designed for such payments and we cannot think of a better way than to award participants that produce useful results with the ultimate privacy coin, Monero.

The Idea

We have integrated the Metabase software into our backend and integrated it with data from the Sentinel blockchain. Metabase allows for easy construction of data metrics, charts, graphs, maps and many more interesting statistical insights into a data set. We have constructed node maps, node uptime charts, node decentralization pie charts, node ASN pie charts, timeseries, and many more interesting analytics to peer into the Sentinel Network.

On September 12th, 2023 we released our Node leaderboard see here:

This leaderboard made use of the query builder inside Metabase to construct the final results shown above. The design of the query made possible by the Metabase query builder can be seen as follows:

The Challenge

If you haven’t already signed up for MathNodes Metabase (MnM), please head over to https://meile.app and sign-up for a free account at the bottom of the page. An e-mail verification will be sent to your provided e-mail address and we contact the winners via e-mail so it is essential that you use a reliable e-mail account. Feel free to use a psuedonym as your name if you prefer to remain anon.

Head over to the Sentinel Analytics section and find the Node Leaderboard query and open it

You will be presented with the results of the constructed query. Click on the ‘Show Editor’ icon to bring up the query builder so that you may begin the challenge.

Once opened you will be presented with the MnM query builder interface as displayed earlier and below as a reminder.

Now, we finally get to the point of what we want you, the curator, to do to receive the Monero reward.

Node Leaderboard – Bandwidth Metric

We developed the Node Leaderboard for hourly subscriptions. Using the above instructions we want you to alter this query, using the query builder, to construct a node leaderboard based on two data points:

• Allocated Bandwidth
• Consumed Bandwidth

Use the Node Leadboard query and adjust it so it summarizes each of those data points. Once you think you have solved each of these two challenges, save the queries, with a different name so you don’t overwrite the Hourly Node Leaderboard. Preferably the query names should be

• Node Leaderboard – Allocated Bandwidth
• Node Leaderboard – Consumed Bandwidth

If we tell you any more of what to do, we would give away the whole challenge.

The Reward

Each query will be awarded 0.15 XMR for a total of 0.30 XMR and we will decide the winner if there are multiple users who created the same query based on timestamp and accuracy. We will e-mail the user with instructions to receive the bounty shortly after we announce the winner(s).

Good luck to all who attempt his straightforward challenge!

Contact

If you need to contact us in anyway please visit the MathNodes Telegram Channel or Discord Channel from the links in the header of this page.

Staring 10 July 2023, MathNodes will be posting bounties for pull requests to our code base. The bounties will be paid in Monero or Pirate Chain, whichever the user chooses. The bounties will range from 0.1 XMR to 3 XMR depending on the amount of work required.

The bounty amounts and specifics can be found on the issues section within our GitHub repositories (https://github.com/MathNodes) and also in the bounties channel within our discord server (MathNodes Discord) aimed at listing all bounties and their completion status.

All bounties will be paid after receiving a pull request to the respective project and only after examination and final testing by our team of developers that are responsible for the project. Most projects are written in python with some exceptions for Golang and Rust.

The first bounty is for 0.25 XMR; is a good first issue and can be accomplished by a novice python programmer. It aims at reducing the amount of queries to our API servers for a particular data value. It would be more efficient if we didn’t query each time and only sent a query request for the respective data value when the table does not contain the information. The first of our many bounties to come can be found here:

Continually check our bounties channel in our Discord server to find out the latest bounties offered by MathNodes.

We hope this will bring more developers to work alongside us and with us to develop strong applications and utilities for Sentinel and other blockchain networks!

MathNodes Discord

MathNodes GitHub

There are many reasons why you would like to switch wallets:

• Different wallet with a different source of funding (IBC Tokens)
• Wallet is used for other means than just DVPN usage
• Deciding to use a primary wallet solely for DVPN subscriptions

This fix will always work and will be necessary until we have added support for removing wallets. It is our intention to be able to handle numerous wallets so the user can switch between them within the app. We expect this to be rolled out in version 1.5 or 1.6 in the coming months. Until then, please use this guide as your means to removing your current wallet from Meile.

Windows

There is a simple fix to removing the wallet in Meile on Windows. Simply navigate in Windows Explorer to C:\Users\username and delete the .meile-gui folder. This will in effect restore Meile to it’s default settings upon next launch.

Linux

Similar to the Windows approach this one is directly straight forward. Open up a terminal window and run the following command

rm -rf ${HOME}/.meile-gui

That’s it! Now re-launch Meile and it will return to it’s initial settings.

Mac OS X

Again, a similar approach to Windows and Linux. Open up Finder and navigate to your home folder (Command + Shift + H). Next you will need to tell Finder to show all your hidden files, press (Command + Shift + . ) You will see in Finder a directory .meile-gui – delete this folder and re-launch Meile and it will return to it’s initial default. Simply restore or create a new wallet to continue using the services.

Or for the experienced user, open up a console window and run

rm -rf ${HOME}/.meile-gui

Simply re-launch Meile and restore or create a new wallet.

Please follow the steps in the previous post about how to get started using v2ray as the same method applies within this post. Soon we will be able to provide a client which allows users to pay for our services to access an open internet. We are working on integrating v2ray in our Meile suite and hope to have something ready by the end of the year. Check back to MathNodes for future updates and progress reports.

Telegram

Once you have set up your v2ray client in your terminal or command prompt, getting it work with Telegram is as straightforward as configuring your browser as shown in the previous post.

First open Settings and navigate to Advanced and click on Connection Type

Click on Custom Proxy and enter in the proxy details just as you did the browser

If all went successful Telegram will let you know you are connected to the proxy

Android

Download Termux: https://github.com/termux/termux-app/releases/download/v0.118.0/termux-app_v0.118.0+github-debug_arm64-v8a.apk

Enable Storage Permission for termux:

Open termux and run the following:

pkg install wget openssl 

Press enter when prompted

Get and install v2ray:

mkdir v2ray && cd v2ray && wget https://github.com/v2ray/v2ray-core/releases/download/v4.28.2/v2ray-linux-arm64-v8a.zip && unzip v2ray-linux-arm64-v8a.zip

Get the v2ray config

wget https://raw.githubusercontent.com/MathNodes/v2ray_configs/main/client_ukraine.json

Edit client_ukraine.json with your parameters:

nano client_ukraine.json

And edit these lines with your setup

"listen": "192.168.1.24", // Edit with your computer's IP address
"address": "45.153.229.92", // Address of your V2Ray server. May be IP or domain address.

The listen section can be found by running

ifconfig

Set the address to one of the following:

45.142.215.110
62.3.12.142 
45.153.229.92

Then run v2ray:

./v2ray --config=client_ukraine.json

Finally, to ensure this runs in the background as long as your phone is charged, set the “Acquire Wakelock” for termux:

Set your proxy settings in your browser or Telegram to that of the client.json file as shown below (Telegram):

We wish the citizens of Iran all the best. Please feel free to join us in our Telegram Channel (https://t.me/MathNodes) or our Discord Channel (https://discord.gg/HQrHXZJHQq) and chat with us on how we can help you or improve our services.

Meile is our dVPN client for Linux & OS X and we will be rolling out releases through the rest of the year. We expect to have v2ray integration before the turn of the new year which will be a paid service (don’t worry, we are inexpensive), and will be hosted on the Sentinel blockchain. Look for us in our Telegram or our Discord servers and come chat with us. We would love to hear what you have to say!