Tag: smartphones

Real time body camera system – Server Storage – part 3

January 3, 2022 /

In the last two parts of this series, we discussed our network protocol and the architecture of our body camera system. We shall discuss our backend recording and streamers service in this final part. After that, we shall present the budget we burnt for this MVP, and finally, we shall discuss why it did not work.

There are multiple server video streaming solutions across the market. Unfortunately, most of them require installing new desktop software or plugins. At the same time, we saw that no video storage format is codec agnostic and could support multiple frames using different codecs. All these weaknesses forced us to develop our storage format for our videos. After a reasonable amount of time of thinking about what would be the format we need for this kind of work, we formulated the following requirements:

  • Blazing fast append: We wanted to write down the incoming frames as fast as possible. Every slowdown of reindexing the frames would decrease performance and increase the cost.
  • File-based:  Storing a significant amount of data into a database is the wrong approach for media-based files. So the file format had to be binary based. Because of the previous requirement, we had to skip the index. Every index recalculation would end up in a lousy performance.
  • To support telemetry: We did not stream only video and audio data, but we also streamed telemetry. There had to be a way to stream its frames as well. Plus, there were use cases in which the user of the body camera could want to stream only telemetry, but not video.
  • Websocket streaming: Since we can not support another streaming format, we decided that streaming from our server to the web browser clients in the headquarters will be based on WebSockets. To do this properly, we had to implement our video player.

Fortunately, if we analyze our network protocol, we can see the following characteristics which will fulfill the requirements:

  • Partitioning: Every network packet has a unique user id and date. And that is enough to determine the filename of the stream uniquely.
  • Counter: Every network packet has a unique counter value, and this value is attached to the date. At the beginning of every day, we moved the counter to zero. If we analyze further the logic of this counter, it could be used as an index key, by which we can sort by time the whole stream.
  • Supports telemetry: Our network protocol supports telemetry by default.
  • Supports WebSockets: We can reuse the same binary message we received from the Android device for WebSocket streaming. The message must be just encoded properly for WebSocket streaming.
You can see the modified version of our frames container on the diagram. It follows the header:body format, where the header represents a metadata structure for the next frame. By iterating the whole file, we could index the metadata into our server’s memory

With the information from the previous bullets, we can define the following logic. We append every incoming packet to its corresponding file on the filesystem, similarly to what pcap is doing with the network packets. At the same time, another process is reading the file and building the index in memory of our service. And the service uses this index to restream the recorded network packets through web sockets to the web browser player.

To implement the described logic, we decided to build the following system modules:

  • UDP server listener module: The idea of this module is to listen for UDP packets and reroute them to a concurrent queue. The FileWriter module later consumes this concurrent queue.
  • Concurrent queue module: Having in mind that we can have multiple process workers, instead of using mutexes or any other synchronization mechanisms, we decided to communicate using queues between the processes.
  • FileReader module: This module’s primary duty is to read the file packet by packet, using the already loaded index.
  • FileWriter module: The idea of this module is to take the packets from the queue and store them into the file. Partitioning per file per queue was implemented, and every file had a FileWriter process.
  • Indexer module:  It reads the file and indexes the network packets into the memory. After that, it is used by the Streamer module to stream data.
  • Streamer module: This was a collection of processes that started by given offset and used the indexer module to send data to the WebSocket server.
  • Web browser player module: The module was used to decode the network packets coming from the WebSocket server and play video and telemetry data in the browser.
  • Synchronization module: The idea of this module was to provide a way for the synchronization of missing packets between the Android device and the streaming server. We used the index module to return a given user and date for which frames are missing.

One can easily modify the proposed architecture to support cloud deployment and high scalability by replacing the concurrent queues with message brokers and the local filesystem with GlusterFS.

You can see a sample system architecture on the diagram describing the listed components. Arrows represent the data flows and how the data passed through the system

After we finished the technical details of the implementation, let’s discuss how much it cost for us to implement the MVP:

Budget:

  • Android device (200$): We decided to use a standard Redmi 3 device. It supported all the needed features, and it had an excellent battery.
  • Extended battery development (3000$): We developed two battery versions because the first one was not good enough, and our hardware vendor did not provide a quality job. We had to switch vendors, etc.
  • USB Camera (200$): Fortunately, we used an already produced board, so the price was relatively low. Still, we had to buy multiple cameras until we found the most suitable one.
  • 3d printing (400$): 3d printing of multiple prototypes is expensive. And we had to try with various variations.
  • Camera mounts (30$): The camera mounts were already manufactured.
  • Software development (23000$): One developer spent a whole year working part-time on this project. He implemented the backend server and the mobile application for the Android device.
  • Hardware development (8000$): Our hardware guy spent a couple of months developing proper housing and an alternative battery unit for our Android device.
  • Business development (1500$): Fortunately, we did not spend a lot of money on business development.

So we managed to implement the technical MVP for a total cost of 36330$. We tried to sell it, and we failed brutally.

Why we failed

As a team without experience in developing hardware products, we made many errors. Fortunately, it was our first and last try at selling a hardware product. We took our lessons, which I shall list:

  • No business need: For every successful product, you need a local business need, with which you can test your idea and see whether you will have traction. Burgas is an almost crime-free city, so no need for such a system.
  • No hardware ecosystem: There is no ecosystem of electronic hardware manufacturers in Burgas. So you become dependent on people you do not know and even have never met.
  • No delivery pipelines: Making hardware depends on your components delivery pipelines. We did not have any established channels and no partners with such.
  • No investor: Hardware startups are not for bootstrapping. You need a good amount of money to hire the proper people and to make sure once you have MVP, you can buy a good amount of items. Hardware items supply can end, and after that, you have to redesign your solution.
  • Wrong paradigm: Hardware products do not scale so much as digital ones. It will help if you have a good global distribution network and marketing to do it successfully. Being in the 4th city by size in Bulgaria, with 200,000 people, did not help.

In conclusion, despite the problems, we managed to produce MVP, which is a piece of fantastic news. Unfortunately, we could never sell this MVP to anyone for the listed reasons. Looking at the good side of things, we learned what mistakes to avoid when penetrating a market. It helped us with our following products. 

Real time body camera system – Camera Device – part 2

October 14, 2021 /

In the last part, we finished the description of our network protocol and its advantages over other encrypted video streaming protocols. In this part, we shall discuss how we created our hardware prototype for the body camera system and what performance problems we had to resolve when we implemented the software part of it. At the end of the article, we shall show you how much our prototype costs and a sample budget for doing something similar.

But before that, let’s first see what our competition was and what features they had for their cameras.

Axon Body 2

The Axon Body 2 is a camera system incorporating an audio and video recording device. This camera is designed for use in harsh environmental conditions encountered in law enforcement, corrections, military, and security activities. The Axon Body 2 camera is designed to record events for secure storage, retrieval, and analysis via Evidence.com services. The recorded events are transferred to your storage solution via the Axon Dock or by using Evidence Sync software installed on a Windows computer.

  • HD Video and Dual Audio Channels: Record in low-light and HD, and make voices more distinct with automatic tuning and noise reduction.
  • Wireless Activation: Axon Signal reports events, like when you open the car door or activate the light bar, so your camera can start recording.
  • Wi-Fi & Bluetooth Connectivity: Use Wi-Fi to stream videos and Bluetooth to assign metadata.
  • Mobile App: Connect with Axon View to stream, tag, and replay videos from your phone.
  • Unmatched Durability: Handle in extreme weather and brutal conditions.
  • Full-Shift Battery: Record for more than 12 hours.
  • Axon RapidLock Mounts: Keep your shot steady with versatile mounts.

Motorola V300 Body Camera

This camera is built specifically for law enforcement. The V300 continuous-operation body-worn camera is ready to go when you are with its detachable battery, 128GB of storage space, wireless uploading, and Record-after-the-Fact® technology. Integrated with the technology you use daily to enhance your focus and combined with powerful device and evidence management software, the V300 body-worn video solution enables you to capture every encounter. 

  • Detachable Battery: Easily change the V300’s rechargeable battery while on the go. Keep an extra battery at the ready for unexpectedly long shifts, extra shifts, or part-time jobs where a body-worn camera is required.
  • Natural Field of View: Eliminate the fisheye effect from wide-angle lenses that warps video footage. Our distortion-correction technology provides clear and complete video evidence.
  • Built-in Display: A clear LCD on the top of the camera allows easy viewing of device status.
  • Absolute Encryption: Elevate your data security with encryption at rest and in transit. The V300 guards your data and your reputation.
  • Rugged & Durable: Tested ruthlessly to survive in a public safety environment, the V300 is shockproof and waterproof to IP67.
  • Automatic Wireless Upload: Send critical video back to headquarters while still in the field. When docked in the car, the V300 body camera uploads to cloud-based or on-premise evidence management systems via wireless networks like LTE and FirstNet, anytime, anywhere.

During the time of development, these were the two main competitions. Both of them lacked the real-time streaming support we wanted. However, both of them had pretty exciting features, without which our solution would not have enough commercial traction. 

After a good amount of market analysis and tests of different technologies, we decided our body camera system to have the following features:

  • Full-Shift Battery: Record for more than 12 hours.
  • Automatic Upload: Send critical video back to headquarters while still in the field.
  • LTE Real-Time Streaming: With adaptive bitrate, we could make our camera system send data during the whole shift.
  • Rugged & Durable: Tested ruthlessly to survive in a public safety environment
  • Built-in Display: A clear LCD in the camera system to allow easy viewing of system status.
  • Absolute Encryption: We wanted data security with encryption at rest and in transit.
  • Fisheye Field Of View: We wanted our camera system to support more than 100 degrees field of view.
  • Low Light Vision: Having in mind that most of the crimes happen during the night, we wanted this feature.

But we had a problem. Being a small, underfunded team located in Burgas, we did not have access to many hardware vendors, nor did we have the hardware team who could implement a body camera system from scratch. We had to take another approach. After a couple of weeks of analysis, we decided to implement a pluggable system using manufactured customer devices. The final system design consisted of the following components:

Hardware

  • Android-based hardware device: For the last decade, almost all Android devices have supported USB On-The-Go. USB On-The-Go (USB OTG or just OTG) is a specification first used in late 2001 that allows USB devices, such as tablets or smartphones, to act as a host, allowing other USB devices, such as USB flash drives, digital cameras, mouse or keyboards, to be attached to them. USB OTG allows those devices to switch back and forth between the roles of Host and Device. A mobile phone may read from removable media as the Host but present itself as a (USB Mass Storage) Device when connected to a host computer. In short, we could attach a standard USB web camera to a typical smartphone.
  • Body mounted USB camera: Here, we had quite an interesting problem. Standard USB web cameras are not tailored for body mounting, neither are they durable enough. We spent a good amount of time checking how to solve this issue, and finally, we managed to find a suitable USB camera vendor using Sony-based camera sensors. The vendor could mount any lens to the camera sensor, and the whole board came with a good amount of mounting holes. After that, one of our hardware people designed a custom mountable case for our USB camera and 3d printed it.
  • New extended battery: The standard battery of our Android device was around 4100mah. Unfortunately, after multiple tests, we saw that with every needed hardware capability activated, aka LTE, USB OTG, GPS, and microphone, the Android device was taking around 800-900mah per hour. And this was not enough for the whole 12 hours shift. So we took the extraordinary decision of creating our battery. Finally, we managed to produce a proof of concept 12400 mah battery replacement for our Android device. And indeed, it took 12 hours to recharge.
  •  Mount for cars and bicycles: We wanted our system to support multiple different mounting points. So, to allow this to happen, we bought standard multi-camera mounts for vehicles and bikes and created adapters for our 3d printed camera to enable attachment to the stock mounts. 

Software

On the diagram, you can see a sample architecture diagram of the solution. With that architecture, we managed to achieve 22 frames per second with streaming and encryption.
  • UDP streamer module: This module’s main functionality was sending UDP packets and receiving answers for these UDP packets. It sent analytics data to the Adaptive bitrate control module to decide how to switch between different formats and resolutions.
  • Encryption module: This module was highly optimized to perform hybrid encryption and decryption of byte objects. We managed to optimize the performance, so the module supported encryption and decryption of real-time h.264 frames coming from the USB module.
  • Network protocol module: Main functionality here was to construct and decode UDP datagrams messages. It used the encryption module to encrypt the data before sending it to the UDP streamer.
  • Adaptive bitrate and codec control module: This module controlled what type of compression strategy to use to ensure that the headquarters will receive data no matter the LTE signal. 
  • Objects pool module: The idea of the module was to reuse different bytes arrays during the lifecycle of the h.264 packets. With around 24 frames streamed per second, creating and destroying many bytes arrays would entirely kill our application.
  • USB camera module: This module wrapped the communication and handling of the USB video camera bus. The idea was to support multiple different cameras and formats here.
  • Telemetry module: In this module, we collected all the additional data we had – current battery consumption, remaining battery time, GPS coordinates, sd card storage, etc.
  • h.264 decoding module: This module’s main functionality was to transfer video frame data in a different format. For example, we supported h.264 frames, png, and jpeg formats. The application was intelligent enough to decide when to switch between the different formats.

We used Java and C++ programming languages for the implementation of all the modules. The only C++ part was the USB camera module because of the low-level communication with the USB bus. 

Let me share some notes on why we decided to use an Android device. We could implement our body camera system using an ARM-based board with Linux installed on top of it. It would dramatically reduce our software efforts. However, from a hardware point of view, most ARM-based boards lacked good CPUs, battery support, and housing. Not to mention, the development of a custom ARM board was entirely outside of our budget. Fortunately, our software was designed this way, so we could easily switch the hardware platform in case of investment or more considerable client interest.

In conclusion, our body camera system managed to fulfill our initial requirements for MVP. It worked well, and we made multiple videos and streams testing it in various environments and locations. Our system even managed to send data through 3G mobile cells in areas where LTE/4G was not supported.

A sample video of how the system works could be found here

Some photos of our POC build. With that build we managed to fulfill our requirements.

Cybersecurity tactics for small teams – Hardware Device Security – part 2

October 14, 2021 /

As you can see from the previous paragraphs, there are multiple ways to penetrate your devices. In the following sections, I shall list some methods of making your devices more secure. You can find the previous part – here.

Hardware Security

There are multiple options for physically securing your laptop and smartphone. At the end of the article, I shall give multiple variants for your budget, but ideally, the essential hardware security upgrades are:

  • Secured Notebook Backpack: There are multiple hardware vendors for securing your laptop backpack. It is essential to know the standard branded bags do not offer enough security options. For example, most backpacks do not provide RFID protection and proper locking mechanism.
  • USB Port Lockers: Port lockers can keep your laptop safe from Rubber Ducky-based attacks. At the same time, port lockers are pretty interesting because they make attackers’ lives more complicated in case of steal. To access the USB port of the device, they have to break the locker, which can damage the USB port and make it unusable.
  • Hardware Tokens: Bussines series laptops usually come with internal TPM chips, which can encrypt your entire hard drive. It is terrific, but if you want better security, it is advisable to encrypt your most critical files using external USB hardware tokens.

Antivirus Software

The average number of new malware programs per day is around 450 000. It is an astonishing number and almost destroys the necessity of antivirus software. Still, it is crucial to understand that the goal of your Antivirus Software is to stop the most critical pieces of malware, but not all of them. Let me list some of the mechanisms your Antivirus Software uses to keep you safe.

  • Malware Database: Every Antivirus program comes with a malware database with different strains of already analyzed computer malware. As we already understood, there are around 450 000 new strains per day. Antivirus companies’ teams keep only the most dangerous strains in the database to keep with the speed of making new strains.
  • Malware Scanner: Usually, every malware tries to gain access to resources, which are not part of its resources pool. Antivirus software can monitor your operating system for such activities and can block them and finally notify you.
  • Operating System Files Hash Check: Some antivirus software can check whether there are changes in your operating systems and notify you and revert the system files for the previous state. It is especially true with Red Hat-based Linux distros.

Open Source

One of the reasons people choose Open Source is the level of security it offers. You can perfectly set up your business to use an open-source stack from the beginning. And this is not only the applications but the operating system and even your hardware. Especially Linux is a beautiful example of how an Open Source ecosystem can increase its security by being open. Instead of using pirated software, you download it from a free repo, which has the source code of the app already reviewed. Every major Linux distro has all of its packages signed, and the repo can verify them. But let me list the different advantages an open-source operating system has.



On the diagram, you can see a sample architecture of a Linux system. Usually, SELinux and AppArmor are working on the Kernel level. After version 4.4, Android has SELinux enabled by default.
  • SELinux and AppArmor: SELinux and AppArmor are kernel modifications and user-space tools added to various Linux distributions. Its architecture strives to separate enforcement of security decisions from the security policy and streamlines the amount of software involved with security policy enforcement. Significantly, the fundamental concepts underlying SELinux can be traced to several earlier projects by the United States National Security Agency (NSA).
  • Open Source Repos: All the packages are part of the software repos, maintained by the distro authors. Bigger Linux distros such as Red Hat and SUSE support big security teams to find and patch holes.
  • Open Source Hardware: There are multiple open-source hardware initiatives, including PowerPC and ARM-based processors. It is essential to know those hardware devices attached to your PC come with drivers, and sometimes these drivers can be an entire operating system. For example, server-based Intel Xeon processors come with network-based remote access control.

Budget:

So after we have listed most of the penetration vectors which an attacker can take, we can finish the topic by creating a budget. We will focus the funding towards underfunded organizations with a limited budget for their cybersecurity program. The budget will be per employee.

  • Pacsafe Backpack (190$):  Pacsafe is a brand of travel equipment emphasizing anti-theft features. The company’s products include adventure backpacks, urban and leisure bags, women’s bags, photography bags, luggage, and travel accessories such as straps, cables, and locks. Their middle-end backpacks offer a pretty good level of security.
  • Business Series Laptop (1000$): For this one, I would choose Lenovo Thinkpad-based laptop. It supports TPM and will offer a good level of harddrive encryption. It is essential to mention here that you have to encrypt all of your storage drives, no matter SSD or HDD ones.
  • Laptop Operating System(0$): Here, we shall go with either CentOS or OpenSUSE. I would personally go with CentOS here because of the native SELinux support. If you want to use the Ubuntu operating system, you should live with AppArmor or set yourself SELinux. CentOS additionally support free Antivirus Sofware supporting all the listed features in the previous paragraphs.
  • Smartphone(200$): Here, we shall use any device, which supports LineageOS. LineageOS is an operating system for smartphones, tablet computers, and set-top boxes, based on Android with primarily free and open-source software. It is the successor to the custom ROM CyanogenMod, from which the devs forked it in December 2016. It offers a good level of privacy, including the complete removal of the Google Play Store for the most paranoid ones. Most of the devices officially supported are in the 200$ range.

With a total budget of around 1390$, we achieved a pretty good level of security. Still, a determined attacker can penetrate this setup, but it will take him more time and resources. If you want to improve this setup further, you can add USB locks and hardware tokens. But, again, the improvement will not be much because, in case of hardware steal, hackers would have to break your TPM module, and the TPM modules are designed to resist this kind of attack.

To be continued

Cybersecurity tactics for small teams – Hardware Device Security – part 1

September 1, 2021 /

Please check the previous part – here.

After we already discussed how to assure your physical security and your network perimeter. The topic for the following two parts is the security of your hardware devices. And especially, I shall give you some ideas on how to secure your personal computer and your mobile phone. I shall provide a sample budget for a security-oriented personal computer, laptop, and mobile phone at the end of the parts. In the budget, I shall put the software appliances as well.

But before doing this, let’s have a short discussion of what a computer is and how we use it. The formal definition of a computer is:

A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of operations known as programs. These programs enable computers to perform a wide range of tasks.

In other words, we have a machine, which works with data and can perform operations on it. It is similar to what our brains do for us but in a different way. In terms of computer security, it is essential to understand that your computer is a data carrier and data generator. The goal of your security awareness model is to protect the data and the generator logic. So we have to treat our computers the same way we treat our brains when we don’t want to share data. Aka by making sure we took all the necessary steps to secure access to our information.

So let’s do it. We start with:

Personal Computer/Laptop

We shall discuss the security of laptop computer because it has a more significant amount of attack vectors. We can apply the same list of attacks to workstations.

By definition – A laptop, laptop computer, or notebook computer is a small, portable personal computer (PC) with a screen and alphanumeric keyboard. It is important to note that a laptop is a total nightmare for your computer security policy in the physical security realm. It inherits the traits of all the hardware devices, including the ones related to garbage. Securing laptops is almost impossible, and a dedicated attacker most probably will manage to penetrate the defenses of your laptop one way or another. But let’s list the different attack vectors your laptop has.

On the diagram, you can see a standard data exfiltration workflow. The attacker makes the victim network sending data to a malicious service and, after that, reroute the data to his/her infrastructure
  • Theft: By being mobile, any laptop is a mobile data carrier similar to your paper documents and USB flash sticks. And by that, a dedicated attacker can steal the computer and gain access to your data. It is essential to mention that any encryption mechanism can slow down your attacker, but you can not determine whether it will stop him.
  • Location-based attacks: Companies such as Hak5 promote an exciting set of tools used for location-based attacks. They can penetrate your WiFi network, and even there are devices named RubberDucky. They look like a standard USB flash, but essentially they are cheating your computer that they are keyboard devices and execute a penetration script.
  • Malware: There are many types of malware, but these are most dangerous in terms of cybersecurity: trojan horses and ransomware. Both of them steal your data. In case of ransomware, you have to pay, and at least you receive notification that something wrong happened. In the case of trojan horses, you have no idea what is going on with your data.
  • Misconfiguration: Most of the laptops do not come with proper security configuration by default. Users without formal training can not configure the system, and it remains unsafe until a hacker penetrates it.
  • Pirated Software: Torrent trackers are a terrible place to download software. Usually, the cracked versions of the popular software come with already preinstalled malware. It is highly advisable to use open source or paid products.

Listed threats are only part of a long list of attack vectors an organization must take care of. Still, they are a good starting point, and if your small team manages to stop them, it can reach a good cybersecurity level.

Smartphones

After the introduction of IBM Simon, the smartphone industry had rapid growth. These days, devices are as powerful as a ten-year-old computer and can perform various tasks, which people kept only for computers for a long time. It is fantastic, but they are even worse in terms of cybersecurity than your laptop. They inherit all of your laptop’s problems with even smaller size and limited control over the hardware. They are a nightmare in terms of computer security. But let me list the different attack vectors which your smartphone can introduce:

  • Outdated Operating System: To further push technical progress, hardware vendors usually discount older than four years old devices. And by discount, it means that these devices do not receive security patches and the latest version of their operating system. This approach leaves thousand of people without proper cybersecurity defenses.
  • Laptop Attack Vectors: As a less powerful computer, every smartphone inherits a laptop’s security problems. Even worse, once you store your data in your smartphone’s internal memory, it is almost impossible to erase it securely.
  • Conversation Sniffing: Hackers can use your smartphone to sniff your daily conversations by being constantly held near to you. Many hardware vendors implement security measures versus this kind of attack, but people must still be aware that such an attack is possible.

Next part is here