If I would like to keep my work secret in my computer and I don't use Internet, is it possible for a cracker to steal my data via electric wires or a wireless connection?

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    I can use electric wires to connect two telephones, then have an insider speak the secret information into one telephone while I listen to the other one. Does that count? Commented Nov 1, 2015 at 23:31
  • 1
    so, I would assume your work could be worth stealing. Are you posting this question from your computer?
    – njzk2
    Commented Nov 2, 2015 at 0:52
  • Could you clarify what you mean by "don't use the Internet"? Do you mean you won't ever connect the device to a network, or do you mean it will be connected but you won't open the browser, or something else?
    – jpmc26
    Commented Nov 2, 2015 at 6:45
  • A wireless connection: absolutely, no question. Power wiring-related stuff? That's... a very interesting question. See WoJ's and Corvus B's answers below. (Although, from a practical standpoint the chances that an ordinary person would be subject to such very high end attacks are very, very low.) Commented Nov 2, 2015 at 9:38
  • By "wireless" do you mean through an existing wireless protocol as Blutooth or Wi-Fi, or do you mean straight through electromagnetic waves emitted by your computer? Please clarify this in your original question.
    – dan
    Commented Nov 2, 2015 at 19:20

6 Answers 6


First of all, a cracker is considered somebody that reverse engineers software in a way where copy protections or nags screens are removed.

From Wikipedia:

Software cracking (known as "breaking" in the 1980s1) is the modification of software to remove or disable features which are considered undesirable by the person cracking the software, especially copy protection features (including protection against the manipulation of software, serial number, hardware key, date checks and disc check) or software annoyances like nag screens and adware.

Technically it is possible that someone could steal your information and/or data if the attacker resides within your LAN. For example for wire tapping, I use the following hardware:

Wire Tap

By placing this device in the network, all packets can be captured. However, this specific hardware is not necessarily required. It is also possible to strip the Ethernet cable and directly tap the RX and TX wires.

From a WLAN perspective, it is possible if someone has access to your WiFi network to put their network card in promiscuous and use Wireshark or a similar product to capture all WiFi traffic. More on that can be found on the Wireshark page: https://wiki.wireshark.org/CaptureSetup/WLAN

Having said that, the likelihood of something happening to you, I consider slim to none. Unless you're really paranoid, disable all your network communication devices (although there are other methods of obtaining information, but this requires very expensive equipment)

  • 14
    Your use of an article on "cracking" to correct usage of "cracker" is not very convincing and does not match widespread usage. Since the word is ambiguous, however, it might just be better to advise OP to use the word "attacker" that would actually be used in infosec discussions. Commented Nov 1, 2015 at 17:22
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    Initially (~'90s) "cracker" was the bad guy and "hacker" someone who was what we would now call a geek. With time "hacker" became the bad guy and "cracker" vanished. So the OP's usage of the wording is correct.
    – WoJ
    Commented Nov 1, 2015 at 17:48
  • Indeed, where I work we still use the term "cracker" to mean "bad guy" and "hacker" to mean generally anyone else. Actually, I've seen this use recently only the Erlang mailing list, so its not obscure (any more obscure than Erlang is, anyway). Maybe it is generational; most of us are over 30. This is the meaning I grew up with as well -- and am still sort of weirded out when the mass media states "a hacker stole credit card data". Anyway, warez kiddies are "crackers" indeed, but it is just one form of a very broad spectrum of cracking; one that doesn't appear to meaningfully exist today.
    – zxq9
    Commented Nov 1, 2015 at 23:38
  • @R: I agree with attacker, as far as the "cracker" what's the difference between a hacker and a cracker? However, I don't want to start this discussion here as it is completely off topic.
    – Jeroen
    Commented Nov 2, 2015 at 6:06
  • @zxq9 mass media states "a hacker stole credit card data" Could be that "cracker" has another popular connotation unrelated to computers and it's to avoid any confusion between hackers and Caucasians. Just speculating, however.
    – user72066
    Commented Nov 2, 2015 at 22:16

Yes, this is possible. It is not an easy task, though, and you are not likely to be a target.

There are series of equipment which are shielded so that such attempts are more difficult. They follow sets of standards called TEMPEST.

  • 4
    Worth adding to this very correct answer: part of being compliant with TEMPEST includes physically observing the wires. Anyone with physical access can do things that are undetectable without such physical observation. The TEMPEST enabled systems are all locked in vaults to limit access by third parties, and inspected regularly.
    – Cort Ammon
    Commented Nov 1, 2015 at 18:14

Data can not normally be stolen via your power lines. There is no interface for data transmission between a normal computer and the power line. Hardware is made that can provide such an interface, but someone would have to have physical access to your machine, and install that hardware in your computer. Phone line and power line networking

If you have a LAN, either wired or wireless, then someone on your LAN could steal data. If your computer has wi-fi, but you do not use it, you can turn the hardware off. At least, you typically can. There might be some computers with wi-fi and no way to turn it off, but I do not know of any. Note that this is not a trivial effort (stealing stuff). Without internet contact you are unlikely to get malware installed by someone else to make stealing your data possible. LAN traffic can be intercepted, but this is again, not easy.

Keeping a computer off the internet is a very good way to keep things private. Locking that computer out of your LAN is even better. For instance, I still run outdated Windows machines for some old software - but I set the firewall to completely block them from using the network. Unless someone gets physical access to them, they can not be hacked into.

Also, of course, good passwords, and encryption are your friends.

  • 1
    Depends on what you mean by "data". While isn't possible to pull arbitrary data off the hard drive, tt's potentially possible to discern keystrokes via power analysis. It's also possible to obtain clues as to encryption keys via the same.
    – Compro01
    Commented Nov 1, 2015 at 18:17
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    Technically, you have a good point. However, the power analysis still requires hardware installation inside, or close to, the target machine. I honestly felt that adding the "close proximity" modifying clause was TMI and not particularly useful. The laser attack has been demonstrated, but it seems to me it would be exceptionally difficult to use in real life. Not to mention that it could be physically detected by the target's user. I would think burgling the premises and installing a keystroke recorder would be far easier and more efficient. So, TMI again.
    – Mark G B
    Commented Nov 2, 2015 at 15:58

There is a principle called Van Eck phreaking where a receiver is placed near the target machine to collect and transmit the changes in the EMF caused by operating the target device.

  • Interesting, nothing some proper isolation can't fix though (like concrete walls and aluminium foil) Nice to know that this tech is out there though, I was just thinking about it the other day.
    – Cestarian
    Commented Nov 4, 2015 at 12:49
  • @Cestarian I actually first came across it in the book Cryptonomicon and thought it was just a plot device invented by the author but it bugged me that much I had to research it. Turns out its real.
    – Burgi
    Commented Nov 4, 2015 at 12:54
  • Yeah I was thinking about this the other day, or a bit more complex version of it anyways which would scan an area for electrical chips (e.g. in motherboards and smartphones and such) and then read data through them directly (would be hard to do with PCs because of the casings, but laptops and smartphones are mostly isolated with just plastic so easy targets for this kind of thing) I was thinking about it's feasibility, and how to counter it. but I am utterly surprised that similar tech already exists... and there are no perfect countermeasures to it yet.
    – Cestarian
    Commented Nov 4, 2015 at 12:57

No data passes through your power cables, unless you're using HomePlug for your internet connection that is or connecting to another device. It's in theory possible to read your data through tapping your power cable or power supply but it would be so brutally hard to do (next to impossible) that nobody is ever going to try such a thing, literally any other approach would be easier. So it's safe to assume that this won't ever be a worry for the next 100 years at least (possibly for eternity; or at least until power cables and internet cables will be united as one or something like that)

Wireless networking is however ALWAYS hackable either by accessing your router and then using wireshark or something similar to read your packets, or by other more advanced means of tapping your wireless network frequencies technically all unencrypted wireless data is up for grabs since it's literally floating around in the air between your system and your router, and encrypted wireless data while less up for grabs can still be easily hijacked through various means (depends highly on the encryption protocol though how easily, and your router security)

If you are connected to a router or another device with your system, that router or other device which is presumably connected to the internet can be hacked to access your data, if however it is not connected to any other device the only way to hack your data would be physical access, and the only way to keep tabs on that data would be infiltrating the place you keep this device, and secretly insert a wifi or bluetooth device into it and connect it to another device or router for the specific purpose of stealing your data. (Someone would have to want your data REALLY BADLY, and just as badly want to keep it secret from you that they've got your data... not a likely scenario unless you're someone really special who could be a high profile target because of your social status or job)

In other words a lone pc that is not connected to the internet or another device at all is unhackable through remote means unless it has a wireless networking device installed which could be remotely activated (like bluetooth or some types of wifi cards) so for good measure disable any such devices and nobody without physical access can access your data. Encrypt your hard drives, use complicated passwords, etc, etc and the only way into your system besides you doing it yourself would be this.

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Why are you asking specifically about electric wires or a wireless connection? If I worked for a government, major company, or organised crime interested in your work, these would be quite at the end of my list to get your things. You should describe what you are actually afraid of.

For example: If I wanted to steal your secret, didn't mind hurting you, didn't mind that you know about the theft, and knew that you used say a Mac with full disk encryption turned on, which is reasonably hard to crack, I'd sneak into your house and knock you out while you are using your computer. Well, I'd send someone in who knows how to do this :-) The point is here stealing the whole computer while it is unlocked so I don't need any passwords to unlock it.

If I didn't want you to know, I'd sneak in and install some hardware that records all keystrokes on your computer, and go from there.

It's all a matter of how badly someone wants your secrets.

  • This doesn't answer the question. This would work better as a comment.
    – schroeder
    Commented Nov 1, 2015 at 21:23

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