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FAQ (Frequently Asked Questions)

What is Deniable Video?

Deniable Video is a security system that uses advanced encryption to record audio or video in a deniable way. No product on the market affords the same level of privacy.

What exactly does "deniable" mean?

Audio and video are encrypted and stored in a way that does not reveal its existence. It is in your power to confirm or deny its existence.

The recorded video is secured with state-of-the-art encryption to prevent access to it. But Deniable Video goes a level beyond that by making it infeasible to determine — even with sophisticated methods — whether any video or audio even exists.

Why would I need continuous audio/video recording?

The basic reasons are:

You may need an audio and video record to protect against blackmail, extortion, theft, fraud, false accusations, harassment, burglary, and any other kind of crime.

You may need an audio/video record of meetings for all the same reasons that you may need a paper record of meetings and agreements. An audio/video record shows what was said and what was not said; it proves what happened and what did not happen.

Or perhaps you need it just to keep an eye on things.

Why do I need privacy and deniability?

You need privacy and deniability so that video you record is not turned against you in some unexpected way to harass or embarrass you. You retain control to extent of deciding even its existence.

What happens if someone steals the entire Deniable Video unit?

You are protected if the system is lost, stolen, or copied. That is a key reason to use Deniable Video.

Any stolen/lost/copied video can end up on the Internet. A thief may find your security system during a break-in. Your housekeeper, children, or visitors may find it. Think about what might happen to your surveillance footage if you lose control over it (for example, if are away on a long trip, you are in the hospital, you become incapacitated). Unlike other video security systems, Deniable Video protects your privacy at all costs and avoids causing you embarrassment.

What keys/codes are needed to view the video?

To decrypt and view video you need two things: (1) a passphrase and (2) a tiny, easily-concealable USB flash drive that contains the RSA private key and the playback software.

The passphrase (or password), is something you choose when you set up the system.

The RSA private key is a very long string of digits that is randomly and uniquely generated for you when you set up the system. The RSA private key is stored in a file on the tiny USB flash drive that also contains the playback program.

Only with you — using the passphrase and the RSA private key — can review the video. Nobody, not even us (the developers of Deniable Video), have anyway to look at your video.

How is this different than other video security products?

Unlike all other video security products, our design objective has been the maximum possible privacy for the person using it.

The overwhelming majority of video surveillance, video recording, or video security products have no encryption and no protection whatsoever against theft, loss, or duplication. The video is completely available to whoever takes the hard disk, DVD, tape, or entire system. Deniable Video encrypts video in real-time and makes the data worthless to a thief.

Furthermore, no other video security product is deniable. With other products you can always show from timestamps, file names, and log files that they contain video, regardless of whether they use encryption or not.

Does Deniable Video support audio as well?

Yes, Deniable Video supports audio straight out of the box. It is part of the basic system and you do not pay extra for it. The standard supplied camera has a built-in microphone. The privacy and deniability features apply equally to the audio and the video.

How do I position the microphone to get understandable speech?

The microphone is build into the camera in our standard configuration, so you do not need to do anything special with the microphone.

Deniable Video uses audio normalization ensuring it automatically adapts to pick up whatever sound level is available. Hence it is quite capable of recording a whispered conversation in a quiet room.

What is the difference between Deniable Video and other high-end video surveillance systems that have encryption?

Do not assume that encryption automatically gets you privacy. Encryption is used in countless ways that have nothing to do with privacy or deniability. A couple of examples should help:

  • Encryption may be used to protect the password that allows a user to log into a video system. But that does not mean that the video is encrypted. A knowledgeable programmer or engineer would have no trouble extracting all of the video stored in such system by removing the hard disk from the video system and attaching it to another computer.
  • Video may be encrypted as it transmitted from the place where it is captured to where it is stored. This protects against wiretapping but does nothing against someone who walks off with the box that actually stores the video!

Deniable Video is safe from the above attacks above and from much more sophisticated attacks as well.

While encryption is a necessary tool to implement privacy and security features (and we do make extensive use of encryption), it is important to understand how encryption and other cryptographic methods are being used. If other products have encryption at all, it is likely added as an afterthought and used in a narrow way as in the examples above.

Privacy needs to be fundamental to the design if a system is to have any chance of being trustworthy. Deniable Video was designed from the beginning with that objective.

Can I buy it without the deniability feature?

Privacy and deniability are intrinsic to the design. They cannot be turned off. There is nothing wrong with having deniability — it simply means that you want to preserve your privacy to the maximum extent possible and to give zero information to anyone who tries to access your video.

What are the laws concerning encryption and recording of audio and video?

We sell worldwide and as you can imagine, there is no way that we can know the laws and regulations in every legal jurisdiction. Nor do we know your particular circumstances and how you intend to use Deniable Video.

For example, our standard configuration includes a camera with microphone that is not designed for covert use. If you replace the standard camera or microphone with a covert device, or adapt it for covert use, then the laws that apply to you may be different than if the system were used openly. The laws may be different if you use it in your own home versus in your business.

Therefore, we provide no guidance or advice on legal matters. It is entirely your responsibility to check your local laws and regulations concerning encryption, recording of audio and video, and all other questions of law.

Can I buy the system without audio capability?

Yes, at your request we can remove the microphone from the standard camera that we supply, and we can also remove the audio module from the software so that no audio will be recorded even if another microphone is plugged into the system. There is no charge for this if you tell us at the time that order is placed.

How can I be absolutely sure that no one will hack into the system over the Internet?

The security provisions against any kind of remote hacking are very high. The Deniable Video never transmits unencrypted video; in fact, it is incapable of decrypting the video since it does not have the necessary cryptographic information (the RSA private key) needed to decrypt video.

When you watch video remotely over the Internet, the video is decrypted at the personal computer where you are located. Only you can view it there.

If you do not need to review your video remotely, you do not need to plug Deniable Video into the Internet. Deniable Video works perfectly well as a standalone system. In this case, you can watch the video by plugging a network cable (an Ethernet cable) directly from your laptop to the Deniable Video unit.

Is the source code available?

We are committed to openly publishing source code, data formats, and technical papers necessary to understand the design and to verify the privacy and deniability features. Until we publish, we offer any customer access to this information under a non-disclosure agreement and a fee to cover costs.

Why is the system so expensive?

If you compare Deniable Video to high-end video surveillance systems, you will see that it is not at all expensive. It is a complete system; many other systems are sold component by component. You are getting high-quality video, not awful convenience-store-quality video. It also includes audio, a feature found in few systems.

But most importantly, you are getting deniability — a feature that no one else provides. Very significant effort has gone into the security engineering and software development to create the privacy and deniability.

Are you saying that there is no way that the system can be defeated?

Nobody can make statements of absolute certainty about such issues. There can be ways to defeat this or any security system that are beyond our control. For example, you may be coerced or tricked into revealing your passphrase and turning over the USB flash drive that stores the RSA private key. We do say, however, that Deniable Video is better for privacy — much better — than anything else on the market.

How difficult is it to break the codes?

The encryption used is state of the art (4096-bit RSA, 256-bit AES, and 256-bit Serpent) and designed using well-established principles, carefully chosen protocols, and thoroughly vetted crypto libraries. An upcoming paper will discuss the crypto design at length.

The encryption algorithm and the key length is not the whole story because good security and good privacy come about from many things being done correctly. Deniable Video uses military-grade crypto, but also considerable engineering has gone into using the cryptography correctly and into designing the system with privacy as the prime focus.

What additional steps can I take to protect my video security system?

You need to keep the USB flash drive hidden when you are not using it. You should also choose a good passphrase; setting a passphrase is optional but we recommend it. An adversary who steals the Deniable Video system, or duplicates its contents, needs both the passphrase and the USB flash drive to compromise the security. You need to ensure that the personal computer or laptop used to view the video is not infected with a virus or other malware; you should run anti-virus and anti-spyware software on that computer and keep up with the latest operating system updates.

How do I erase all video forever?

In the playback program, click the button that says "Wipe stored video" — and then click the confirmation — to permanently erase everything. The video is then gone forever and even the fact that video once existed is not demonstrable. Revealing your passphrase and the USB flash drive after a "wipe" does not make it possible to recover video or to demonstrate prior existence of video.

How long does a wipe take?

Within 30 seconds of initiating the wipe, all video becomes irrecoverable. In those 30 seconds, all cryptographic key material is overwritten in a cryptographically-secure way.

The Deniable Video system then goes on to overwrite the entire video storage area with random data for an extra margin of safety. This extra step can take up to 2 hours. If you do not want to wait that long before using Deniable Video again, just hit the reboot button to cancel this "random fill".

What do you recommend I do if my Deniable Video is lost or stolen?

If your Deniable Video system is lost or stolen, or you suspect that its data was somehow copied, you can make all the video irretrievable by destroying the USB flash drive. First sanitize the USB flash drive using the shred program that is supplied on the flash drive. For an even greater margin of safety, first sanitize the USB flash drive and hit with a hammer until all the chips inside are pulverized.

A short technical explanation: The shred program overwrites data before deleting it, but there is a theoretical possibility that so-called "wear-leveling" on the flash drive may have left a hidden copy of the private key. That is why — for maximum safety — we suggest crushing the flash drive.

If someone tries to access the video without the right RSA private key or passphrase, the player software says, "Wrong key or nothing recorded". Doesn't this message demonstrate that the Deniable Video system contains video but that you just cannot view it?

No, it proves nothing because the same message appears in all of the following cases:

  • It has no video (i.e., the Deniable Video unit contains only random data as it did when the system was first delivered to you or after a wipe)
  • It has video that you cannot view (because you do not have the right RSA private key or passphrase)
  • It once contained video
  • It never contained video
  • It was recently wiped
  • It was wiped a long time ago

All of those cases look and behave identically. Even a technically sophisticated organization who have the resources to analyze the hard disk byte by byte cannot conclude which of these cases is the one that they are facing.

Will the video be corrupted in the event of a power failure?

The Deniable Video system is designed to be safe in the event of power failure. The three minutes of video shot immediately before the power failure will not have been saved (because it was still being processed in memory) but all other video is safe. As soon as power is restored, the Deniable Video system will start up and resume recording automatically.

How long does it record?

The system never stops recording: the newest video simply replaces the oldest video when the system is getting full.

The Tech Spec page has the estimated capacity (which is variable due to compression). Images without much motion or activity compress to a smaller size and therefore give more recording time.

You can add as much extra storage as you wish by plugging in external USB hard disks. Contact us to get a list of supported external drives. All external storage is automatically encrypted at the same level of security and privacy as the internal hard disk.

What happens if the Deniable Video unit is lost, stolen, copied?

Your video remains secure so long as you have not lost control over your passphrase and the USB flash drive which contains the RSA private key.

What happens if the USB flash drive is lost, stolen, copied?

Your recorded video remains secure so long as you have not lost control over your passphrase and the Deniable Video unit itself.

Even if you have made a backup copy of the USB flash drive, we would strongly recommend that you wipe the previously recorded video and re-initialize the Deniable Video system by generating a new RSA private key and choosing a new passphrase. You can then start recording new video.

A technical note:
Although you can change your passphrase without affecting the existing video, you cannot change your RSA private key and still keep the existing video. Why not? To encrypt existing video with a new RSA key, we would need to first decrypt it with the old RSA key, but we do not want the RSA private key to ever come into contact with the Deniable Video unit. So as a principle of privacy-safe design, we do not provide a way to do this.

What should I do if I suspect that my passphrase has been compromised (for example, if someone saw me entering it)?

You should change your passphrase using the video playback software. Go to Settings -> Key Management -> Set Passphrase.

What happens if I forget my passphrase?

You cannot recover video if you forget your passphrase or if you misplace the USB flash drive that contains the RSA private key. There is no "back door" or anything that we (the developers of Deniable Video) can do in such circumstances.

You will have to re-initialize the Deniable Video system by generating a new RSA private key and choosing a new passphrase. You can then start recording new video, but the old video will be gone forever.

What is the file format of the video when it is saved or exported?

The audio/video is saved in an Ogg media format container (a.k.a. OGM) using the XviD MPEG-4 video codec and the Vorbis audio codec. This container type and these two codecs are widely supported and are not proprietary to anybody. Free programs available on the web can convert the audio and the video to other common formats if you so desire.

How does Deniable Video compare with audio/video scramblers?

The word "scrambler" usually refers to analog techniques for obscuring audio and video. Today, these old-fashioned analog methods are considered ridiculously insecure. A person with some training can actually understand speech that has been scrambled with simple voice inversion for example.

Deniable Video operates on digital audio and video, and encrypts it with modern cryptographic methods to yield very high security. The recorded data is indistinguishable from random data unless you have the RSA private key and passphrase.

What kind of cameras are supported?

The software currently supports Firewire cameras (with or without built-in audio). For example, almost any camcorder with a Firewire interface can be used as an external camera. Camcorders usually label the Firewire connection by one of these names: DV-out, IEEE 1394, or iLINK.

The Deniable Video hardware also includes built-in interfaces for USB 2.0 and gigabit Ethernet (GigE). A future software update will add the necessary drivers so you can use USB and Ethernet cameras in addition to Firewire.

Analog cameras can be supported by converting the analog signal to digital data using an external video encoder.

What are the specs regarding audio and video quality?

Our standard audio/video configuration looks and sounds approximately the same as good-quality broadcast TV. For video, our standard configuration is 720 x 480 resolution, 12 bits/pixel of color data, at 15 frames/second. The audio is one channel (mono) at 48 kHz sample rate and 16-bit sample depth.

How do you view the video?

You always view the video from an external personal computer (not supplied). As a principle of safe design, the Deniable Video unit itself is not capable of decrypting and displaying the video since it never has access to your RSA private key or to your passphrase.

To watch video, connect a personal computer to the Deniable Video unit, attach the supplied USB flash drive to your computer, run the video player from the flash drive, and enter your passphrase.

If you choose, you can connect the Deniable Video to a router, DSL modem, or cable modem, and watch the video remotely from anywhere in the world over the Internet. This Internet connection is entirely optional; Deniable Video never needs an Internet connection and never downloads software updates or anything else from the Internet.

Any video that Deniable Video transmits to you is always encrypted and is decrypted by the playback software at the location where you watch the video.

The video playback software currently runs on Windows XP, but support for Windows 7, Vista, Mac, and Linux will be available in the near future.

What is on the USB flash drive?

There are actually two very different USB flash drives that we deliver to you.

One USB flash drive contains the Deniable Video system software. This is the operating system, device drivers, audio/video encoders, and the cryptographic, security, and privacy software. You plug this into the back of the Deniable Video unit and leave it plugged it. The only time you ever need to do anything is if we send you a software update in which case you swap the old flash drive with the new one, hit reboot, and you're done.

The other USB flash drive contains the video playback software and your RSA private key. You need to keep this flash drive secure and hidden.

When we refer to the USB flash drive, we usually mean the one that has the video playback software. If we need to make the distinction very clear, we will say Lizard flash drive for the one with the system software, and Turtle flash drive for the one with the video playback software.

Do I have to remember yet another password to use Deniable Video?

The passphrase is optional. If you choose to not set a passphrase, you still have a very high level of security and privacy so long as nobody gets ahold of your USB flash drive. However, we recommend that you set a passphrase so that you have two levels of security.

We sympathize with you that the number of passwords that we all have to remember these days has gotten out control. But in this particular case, a password or passphrase is actually the best way of achieving deniability. A person being coerced can claim that he does not know the password, has forgotten it, or has never set it.

What are some of the design considerations regarding privacy?

This is the subject of an upcoming paper, but briefly some of the features relevant to privacy and security are as follows:

  • The user's RSA private key and the user's passphrase never come into contact with the Deniable Video unit.
  • There is strong separation of data and program on the Deniable Video unit. The hard disk of the Deniable Video unit contains only encrypted audio/video data (or random data) and a very small amount configuration data like the RSA public key (not the private key). There is no software on the hard disk. On the other hand, the Lizard flash drive contains only software; it has no audio/video data or user-specific configuration data. Furthermore, the Lizard flash drive is read-only (a.k.a., write-protected).

    These facts make program verification much easier because it means that:

    • there can be no data leakage or covert channels that store compromising data to the flash drive that contains the system software
    • it is significantly harder to hack system software in a way that can survive a reboot since the system software is not writeable
    • all of the space on the hard disk can be accounted for
    • encryption correctness can be verified by decrypting the data from the hard disk since it follows a straightforward and documented format

There will be much more about the design and code in the future paper.

Is there a way to save video to a DVD or to my PC's hard disk?

To copy a particular video segment to your PC's hard disk, click on "Save As" in the playback program. To copy all recorded video to your PC, click on "Export All Video". After you have saved the video, you can burn it to a DVD, email it, watch it with other media players like Windows Media Player or VLC, etc.

Be aware that video saved or exported to your PC is no longer encrypted. In technical jargon, we say that it is saved as "plaintext". If you want to save video to your PC but want to keep it very private, then you should use a program like TrueCrypt or PGPdisk on your PC. Create an encrypted volume with TrueCrypt or PGPdisk, and then save the video to the encrypted volume. Such an encrypted volume can be burned to a DVD if you wish to create a backup.