Casa Blog - Bitcoin Security Made Easy

Your home is your castle. It's a place where you should be confident that you, your family, and your property are safe against all manner of threats. In order to be secure against attacks, a castle must have defenses — strong walls, a moat, a portcullis, and so on. The same is true for any dwelling in which you may reside.

At Casa we specialize in helping people improve their personal sovereignty and safety. While we're currently focused on private key security for bitcoin, this is only the tip of the iceberg. Many of our clients have expressed concerns about securing other aspects of their lives, including physical security — the following is a direct response to questions we regularly receive.

Because "safety" is relative and depends a lot upon one's perceived threats and budget, home defense is a complicated subject that is unique for each person. In this article I'll cover a variety of options. You should implement the ones that make the most sense for your situation.

To begin, you should research your area to see if you can determine a few statistics. Most importantly , what are the rates of various crimes in your area and what is the average response time of law enforcement?

It’s unlikely that law enforcement will arrive at your home in less than 10 minutes if you report a physical security breach, so you must ask yourself: what will I do to keep my family and property safe if I can’t rely upon anyone but myself?

Think like a thief

There are two types of people who may want to enter your home against your wishes:

  1. Burglars who are just looking for an opportunity to score some valuable items
  2. Violent attackers who are specifically targeting you with the intention of causing harm

The former are far more prevalent, thus you should prioritize defenses to ward off these less motivated attackers. Burglars want to avoid confrontation and prefer to get in and out of a house before anyone is the wiser. It's safe to assume that a burglar is going to break into somebody's home — the question is how to make your home a less attractive target than other homes. We should keep in mind the main factors that a burglar will take into consideration when selecting their next target:

  • Time: The longer they are stuck outside the home trying to gain entry, the more likely someone will notice and they'll get caught.
  • Sound: The more noise that is created when they break into a home, the more likely someone will notice and they'll get caught.
  • Visibility: The easier it is for neighbors/the public to see the home, the more likely someone will notice unusual activity and they'll get caught.

Go outside and inspect your home, both during the day and at night. If you wanted to break in without anyone noticing, how would you do it? Are there unlit/well covered areas that would conceal a break-in attempt?

Defense in depth is important . You want as many features as possible to deter someone from trying to enter your home, and if they do manage to break through, you want alarms to go off to alert you. Think of it in terms of perimeters/walls  —  you want an attacker to have to penetrate multiple layers of security so that you know if they get inside your home, they must be extremely motivated and you will have no qualms with using active defenses at that point.

Passive defense

For deterring the vast majority of common thieves, having a layer or two of light security will be enough to make them reconsider and look elsewhere for softer targets instead of your home. It's not sufficient to only have active defense such as weapons, because the majority of residential break-ins occur between 10 AM and 2 PM while the occupants are at work.


If it’s possible with your home, erecting a fence with locked gates is a great start. The fence should preferably be at least 8 feet tall. You can harden the fence against jumpers by adding a sharp unobtrusive crown along the top — it's far less conspicuous than barbed wire!

If you're fortunate enough to be able to completely encircle your property with a fence, you'll also want to have a decent gate. Don't go overboard on a gate that is far stronger than the fence, otherwise an attacker will just choose to bypass the gate by breaking through the fence.

If you want to take it to the extreme, you can place an anti-vehicle barricade behind a driveway gate. These shallow-depth wedge barriers are rather impressive with their stopping power and robustness.

Hardening doors

First of all, the hinges of exterior doors should be on the interior of the house, otherwise a savvy attacker will simply remove the door from the frame by taking off the hinges.

The type of door matters a lot, as different doors have different weaknesses. Your standard door that swings inward is most susceptible to being kicked in, thus you should ensure that the deadbolt and striker are heavy duty with extra long screws that go deep into the frame. Be aware that residential home builders in some countries like the United States tend to cheap out on deadbolts and strike plates. If you have exterior doors with glass windows, make sure that they use double cylinder deadbolts so that an attacker can't simply break the glass, reach through, and turn the lever to slide the deadbolt open. Don't leave the key in the interior cylinder or it defeats the purpose!

French doors are especially weak and should have their striker plates reinforced. Sliding glass doors also have unique weaknesses and are prone to being lifted out of their tracks. You can add a security bar or less obtrusive security bolt to prevent that from happening.

Make sure there are no gaps between the door and the door frame — these could be used as leverage points to pry open the door with a crowbar.

A heavy duty door jammer is great to use for exterior doors that don't get opened often. I'd also recommend keeping one by the door of your interior "safe room" (likely the master bedroom) where you intend to barricade yourself in the event of a home invasion.

If you're willing to spend hundreds of dollars, consider replacing your exterior door(s) and your interior "safe room" door with steel doors or add a security storm door in front of the current door.

While a burglar is more likely to enter through an unlocked door or break it down than they are to pick the lock, there's no need to make it easy for burglars who have rudimentary lock picking skills. They're not cheap, but you can find high quality locks at Security Snobs.

Hardening windows

Burglars prefer unlocked windows. Don't leave yours unlocked!

Breaking glass is dangerous and creates a lot of noise that attracts attention. However, it is incredibly easy to break the average window as you'll see below.

If it's an option for any ground-floor windows, consider planting thorny shrubs underneath the windows to keep people from approaching them. Thorny shrubs are nature's concertina wire!

Windows can be hardened with an application of shatter resistant film. If you have a professional window film company do this it will get fairly expensive, though do-it-yourself products are available and they work reasonably well. These products won’t stop an extremely motivated attacker but they will slow one down, buying you precious seconds to retrieve weapons, set up other barricades, and call for help.

Here's a test I performed on some cheap do-it-yourself film several years ago:

If you're willing to take it to the extreme and have the budget, you can't beat metal shutters. You don't see them often in America other than along coastal areas where some people have "hurricane shutters" installed, though they are more common in Europe.

Nothing's getting through this window when the shutter is closed!


Lighting is important, not necessarily so that you can see someone approaching your house, but so that any neighbors or bystanders can see what's going on at night.

The great thing about technology is that now it's quite simple to buy dusk-to-dawn lights — you can get bulbs with the light sensors built right into them! If there are other areas that you don't want lit constantly, consider putting them on a motion activated sensor.

Once again, you need to think like an attacker with regard to lighting. As such, you want to ensure that your lighting makes it easy for you to see intruders by not vice versa:

Exterior maintenance

If you're responsible for the upkeep of your home's exterior, don't slack off! Keeping the exterior poorly maintained may attract attention in the sense that it may make a burglar think the residents have left for an extended period of time.

On this note, when you are leaving for a long time you should have a trusted friend/neighbor come by once in a while to pick up any mail/newspapers/packages /advertisements that have been left outside your home since those can also be signals for burglars. You could, of course, notify the postal service and delivery companies of when you are gone, but then you have to ask yourself if you really trust the employees of that service. It's not unheard of for burglars to choose their targets based upon leaked information from delivery service employees.

Portland police say they’re investigating a postal service burglary scheme
The investigation is part of a wider probe involving a man and a woman who have been implicated in a series of burglaries and other crimes in Washington and Oregon.


No safe is impervious to an attacker who has enough time; it helps to realize that most burglars will only spend a few minutes in your house, especially if their entry sets off an alarm. As such, buying a safe that can't be carried off is a big plus. This can be achieved either by buying an incredibly heavy safe or by buying one that you bolt to an immovable object in your house such as a wall stud.

One thing to note about "fireproof" safes: many of them don't actually stand up well to a full blown house fire because they use gypsum as an insulator. The best fireproof safes will actually have concrete insulation in their walls, which of course also makes them far heavier.

Finally, you should ensure that any fireproof safe you buy is also waterproof. In the event of a real fire, it's probably going to have a high volume fire hose pointed at it!

Alarm systems

I would recommend that you stay away from the big name security companies, both for privacy reasons and because they aren’t particularly thorough. They'll put some sensors on your doors and windows and maybe even add video surveillance for a premium, but you have to ask yourself if you want a third party surveilling your property around the clock. Why pay $30+ a month and give up the privacy? You can buy a do-it-yourself system that will call whatever phone number you want.

If you're really nerdy you may go as far as building a security system from scratch using OpenHAB — open source home automation software. There are OpenHAB tools such as ideAlarm that can help you accomplish this.

If you don't have a landline, get a VOIP device that supports Google Voice such as the Obihai OBi200. Of course if you're using a VOIP service as your phone line, make sure that you put your internet modem and router on an uninterruptible power supply so that a thief can't simply cut the power to your house to disable the alarm. If you want to take it to the next level, add a cellular backup communications module so that you don't have a single point of failure for sending alerts.

Finally, if you're on a particularly large amount of land and can't fence it all in with a gate, consider adding a wireless driveway alarm at the entrance to your property.

Surveillance cameras

For a camera system, don’t buy a consumer grade system that you'd find on the shelf at a store  —  much better quality ones are available. Cameras are an incredibly complex topic with many trade-offs; I recommend reading this guide if you want to dig into details.

A few traits I recommend for your surveillance camera system:

  • Look for a 4 megapixel camera that has good low light performance. Note that cameras with higher than 4 megapixel count will perform better during the day but worse at night.
  • It's preferable to have a higher number of cameras that each have a narrow field of view rather than having a small number of high resolution cameras with a wide field of view.
  • PoE (power over ethernet) is preferable to wireless; you're going to need a cord for power anyway. You're far less likely to lose a signal when it's being sent over a wire. Also, battery-only wireless cameras don't have enough power to run 24/7 — they are generally motion activated.
  • If you're in a cold environment you may want a camera with a heating unit to prevent frost or fogging.
  • Buy enough cameras for 360 degree protection of your property. It's better to have "too many" cameras with overlapping fields of view than to have too few, creating blind spots.
  • Outdoor cameras that emit infrared light in order to work in low light conditions actually tend to attract insects and spiders and you'll end up haveing to regularly clean the cameras so that they aren't obstructed. The insects will also set off any motion detection you may have configured! One way to prevent this is to disable the IR emitter on the camera and instead buy separate standalone IR illuminators that you place away from the cameras.

I've had a good experience with the Hikvision DS-2CD2085FWD-I IP Camera paired with the Hikvision 4K POE NVR. Just be careful that you aren't being sold counterfeit Chinese knock-offs! Make sure you buy a NAS-grade hard drive like the Western Digital Red to put in the NVR because those drives are designed to be constantly reading and writing data — they're less likely to fail than desktop drives.

You should be able to find a local tech/electronics expert to help install them if you don’t like running wires yourself. You should set up this system to only be accessible to yourself  — don’t enable any cloud syncing functionality, just use direct IP address and authentication to the NVR to access it. Various cloud-based portals are offered by some NVRs for the convenience they provide for you to be able to check in on your home when you're not on your home's wi-fi network, but they do this by sending all of your video footage to a third party!

Network video recorder software

ZoneMinder software. Source:

You can either buy a dedicated NVR device like the Hikvision I linked above, or you can run your own NVR software on a dedicated computer. There is a variety of camera recording and monitoring software available; I'm not familiar with most of them. My general experience is that free, open source NVR software is highly functional, but you'll probably end up spending more time configuring it in comparison to proprietary hardware and software. Setting up motion detection alerts in particular can be a pain, especially if a given scene has plants that may sway in the wind, or if there is night time traffic whose headlight beams enter your camera range, or if you experience a lot of lightning in your area.

As mentioned earlier, some NVRs will "phone home" to their manufacturers, or even stream all of your footage to another country! If you're tech savvy, I'd recommend creating rules at your router to block any outgoing connections from your NVR to devices outside of your home network.

External intercoms

Some brazen attackers may simply approach your front door and wait for you to open it before barging in. In order to protect yourself from being blindsided in this manner you should have a camera with a view of the exterior of any entrance accessible to the public. Combined with an intercom, you can safely interact with visitors to better determine whether or not they have a good reason to be on your property.

Make a plan

Make sure that everyone in your home knows what to do in case there are intruders in the home. You should barricade yourself in a secure room, call the authorities, and wait. No need to risk your own life by proactively engaging invaders if it's not necessary.

Part of your planning should involve researching the relevant self defense laws in your jurisdiction. There is a wide range of laws in various areas — some have a "duty to retreat" where you may only use violence in self defense if you are backed into a corner. Others have "Castle Doctrine" laws that enable you to use deadly force against anyone who is unlawfully intruding on your property. There are also a range of laws that may dictate how you are allowed to store weapons. I'd highly recommend signing up for a home defense or concealed carry class at a local firearm range — these classes tend to focus more on the legal aspects of self defense than the technical aspects of firearm operation.

This study of 40 US law enforcement agencies and over 3 million calls for service showed that response times are far from immediate. Even for "priority 1" calls where someone's life is in immediate danger the median response time was 9 minutes while the average response time was 25 minutes!

Since 911 calls are a matter of public record, there are many hours of recordings of real-world home invasions available online if you want to get a sense of what it's really like. When seconds count, the police are only minutes away!

Active defense

Man's best friend


An active, loud canine, regardless of size, is a great addition to any home. Sorry, feline fans, but no home invader is going to be scared off by your cat. Even if your dog is not trained to attack intruders, few criminals are going to want to bother to find out whether or not your dog's bark is worse than its bite. In fact, it is often legally "safer" for you to own a dog that is unlikely to bite an intruder—if a burglar is injured by a dog, they may be able to sue you for damages in many jurisdictions! Also, note that aggressive breeds that are often employed as working dogs by military and law enforcement tend to require a lot of training to ensure they don't bite the wrong person! Don't get a "working" dog breed if you aren't willing to put in the work yourself.

Hunting and herding dogs will do well as alert guards who bark when they hear any odd noises. Even small terriers or spaniels can fulfill this duty! You can filter various breeds by their characteristics at the AKC's web site, though I'd recommend adopting rather than buying from a breeder.

Hand-to-hand self defense

To be quite blunt, there are no rules when it comes to life-or-death situations, which is why I don't recommend traditional martial arts for self defense training unless you have a ton of time to spare after learning another practical combat system first. If you want to be in the right mindset—to be capable of doing whatever it takes to defend yourself and those you care about—you ought to learn a street combat system.

Krav Maga or Defence Lab are optimal, as they are designed to disable attackers as quickly and efficiently as possible and they prepare you for being faced with knives, bats, and firearms. An important factor to note about Krav Maga, at least in the US, is to make sure you're attending a school that is teaching unadultered Krav Maga and not some watered-down "cardio Krav Maga." If your class doesn't require that you wear a groin protector and mouthguard, if they don't offer full-contact sparring sessions, in all likelihood you aren't training real Krav Maga.

MMA, BJJ, and Muay Thai are better than Karate or Judo, but they fail in the regard that they don't prepare you for the fact that few real-world fights are 1-on-1. Any martial art that trains you for "ground work"— taking your opponent to the ground and putting them into submission— is setting you up for failure in real-world combat. If you employ such a defense against an attacker, the most likely result is that while you're on the ground, the attacker's buddy will kick you in the head and knock you out. Game over.

That said, it's not a bad idea to train for ground work. Having this knowledge will enable you to escape from a bad situation and get back on your feet, which is the optimal position for both fight or flight. Training with any self defense system will increase your confidence and your stamina, which are great advantages to have!

Less lethal weapons

Firearms may not be an option for you for a variety of reasons. It's worth noting that there is no such thing as a "non-lethal" weapon — pretty much anything has the potential to be lethal given the fragility of human life.

It's best to understand less lethal weapons from the perspective of how they are deployed by law enforcement officers. In practice, LEOs only use less lethal weapons against an armed subject if there is a backup officer who is prepared to deploy lethal force. The reason for this is a combination of the fact that less lethal weapons are unreliable and they generally must be deployed at fairly close range, thus putting the officer at risk of attack if the less lethal weapon proves ineffective.

According to this 2008 study, deployment of less lethal weapons, even by trained LEOs, is far from guaranteed to result in stopping someone. In a significant number of cases, officers end up having to use 2 or 3 rounds of less lethal force before a subject becomes compliant.

According to the same 2008 study, TASERs were only effective about 60% of the time they were deployed by a trained LEO.

To drive the point home further, there are a plethora of police bodycam videos on youtube demonstrating the unreliability of less lethal weapons.

While less lethal weapons are certainly less dangerous to an attacker, the trade-off is that they are more dangerous for a defender because the attacker is more likely to have the opportunity to counter-attack.

Lethal weapons

Lethal force is an even more complicated subject; if you're interested in learning about considerations to take around last lines of defense you can check out my personal blog post on this topic.

Further resources

While this post attempts to be fairly comprehensive it can't cover everything; to go even more in depth I’d recommend subscribing to /r/homedefense/ and browsing the Defence Talk forum.

Closing thoughts

If this all sounds overwhelming, don't worry — you probably don't need an extreme level of security! Remember that the bare minimum to protect yourself against random crimes of opportunity is to be a "harder" target than your neighbors, thus incentivizing attackers to skip your home in search of lower hanging fruit.

For those of you who are worried about securing your bitcoin, note that Casa is designed to help you ensure that your home is not a single point of failure. As such, you need not have extreme home security in order to protect your keys from all manner of attacks and disasters.

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