What’s the best high security lock? – Medeco vs Mul-t-Lock

June 27, 2023

The need for High-Security locks is quite pressing. We are not talking about the threat of break-ins and violent forced entries. That is also quite problematic. What we are talking about is the ease with which locks can be picked by even amateurs. It is estimated that 35% of door entries will show no signs of forced entries. This is a problem, especially when dealing with insurance claims, where companies need to see at least some signs of forced entry. Lock picking remains a serious challenge, but an even bigger challenge is lock bumping . Lock bumping can be easily learnt from many resources and sets of bump keys (also known as 999 keys) can be purchased easily from the internet.

Another overlooked issue is the threat of unauthorized key duplication. For example, it could be the tenant that is renting your basement, or some other friend or acquaintance. All they need is a bare-minimum expenditure for having multiple key duplications which you don’t know about at all! Even your own set of copied keys can be easily compromised if you aren’t careful.

The point is that even amateurs, and non-professional crooks can gain entry quietly into your homes and it is imperative for you to do everything in your power to protect your homes. This is especially true given the desperate situation that COVID-19 has put everyone in. Rioters that are looting shops can very easily start to break into houses. This is where high security locks come in to play!

High-Security Locks are those that provide the best resistance to any unneeded tampering with your locks. For any lock to be considered high security, it needs to undergo the right scrutiny and be given the right security rating. This ranges from Grade 1 (highest rating) to Grade 3 (lowest rating).

Also, as opposed to many myths surrounding them, even high-security locks are not 100% break-in-proof! But they make it almost impossible for your average person doing the break-in to succeed in what they are doing. High-security locks, therefore, need to be chosen carefully to make sure that they truly live up to their name. In commercial settings, high-security locks will be worth the extra price for example.

We are comparing 2 of the most important brands in the high-security locks industry. We have chosen them due to their sheer presence in either the US (Medeco) and international (Mul-t-lock) high-security lock markets.

Medeco
Mul-T-lock

Both brands of high-security locks are very popular. According to various sources, Medeco locks are used in at least 60-75% of the US High-Security market. They have been promoted by the company as the “lock that cannot be picked”.

Mul-T-lock has also been in the business of high-security locks for close to 5 decades. The Mul-T-Lock website shows that they have a presence in 80 countries and 20,000 service centres. They are very dominant in the international market. They are an Israeli company that has a proud tradition stemming from the IDF and a signature trademark with a man with muscular arms morphing out of a key high-security lock key. It is hard to miss!

Both companies are owned by the ASSA Abloy group, which is a Swedish conglomerate.

They both use a similar and familiar locking system, the pin-tumbler design with springs. This is not too different from most locks that you are familiar with. Hence, it will be generally easier for your local locksmith to install either of these 2 brands on your door lock.

Now, for the differences. Both lock systems are quite similar and both companies have great products, but there are certain strengths and failures that each of these lock systems have which give one brand a clear advantage over the other.

Hence, if you are looking for prevention from brute force break-ins, then consider the Medeco Maxum .

Key Control: Medeco has utilized their exclusive use of angled cuts on their keys, and slider combinations to produce millions of key combinations. They have also patented a key control system that makes it virtually impossible to get a copy without your permission. In the case of Mul-T-Lock, an a magnetic strip order card needs to be presented at an authorized dealer for key duplication. Now, Medeco gives you control over duplication, but Mul-T-Lock goes a step further and makes it more rigorous to get a key duplicated. You have the highest level of key control.

Hence, if you are looking for strict key duplication controls, go for Mul-T-Lock.

The most critical test for any high-security lock is lock picking or bumping. You need to be as secure as you can against any lock-picking or lock-bumping incidents. When it comes down to it, a high-security lock's inability to be picked or bumped is what, in the end, defines it as such. Unfortunately, Medeco's performance in this area wasn't all that great. It should be emphasized that neither brand is completely impenetrable, although Medeco's security has been broken. A website devoted to Medeco issues has noticed this! It demonstrates quite clearly how even the most recent M3 generation's security has been penetrated by something as easy as a paper clip, and how older versions (which are still widely used) have major weaknesses. In this case, Mul-T-Lock automatically wins because there haven't been any issues revealed and because it can withstand at least novice lock-picking techniques.

After comparing the three main factors for high-security locks, it is safe to declare that Mul-T-Lock should be the top choice for overall security as it relates to the entire brand. Even while a robust Medeco Maxum lock makes a powerful statement, it is only one product within the entire company, and forced entrance break-ins are more frequent than unforced entry. Medeco is a poor choice due to significant security breaches and a lack of key duplication rules. It makes sense why Mul-T-Lock is praised by local locksmiths and blogs as the best high-security lock.

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Smart locks promise convenience. Keyless entry. Remote access. Control from your phone. But when it comes to security, one question still confuses many homeowners: Can you rekey a smart lock the same way you would a traditional one? Or are you stuck replacing the entire system? The answer isn’t as simple as yes or no. Because not all locks—smart or traditional—work the same way. And understanding that difference can save you time, money, and unnecessary upgrades. Start With What Rekeying Actually Means Rekeying isn’t about changing the outside of a lock. It’s about altering what happens inside. In a traditional lock, rekeying changes the internal pins so old keys no longer work. The hardware stays the same, but access is completely reset. It’s one of the most efficient ways to regain control—especially after moving into a new home or losing a key. But this process depends on one thing: A physical key mechanism. And that’s where smart locks start to differ. Why Traditional Locks Are Easy to Rekey Standard deadbolts and cylinder locks are built for it. Their internal pin systems are designed to be adjusted, reconfigured, and reset without replacing the entire lock. A locksmith can quickly change the key combination while keeping the same exterior hardware intact. This is why rekeying has always been the go-to solution for restoring security without overspending. It’s simple. Direct. Reliable. And in most cases, it’s all you need. What Makes Smart Locks Different Smart locks aren’t just locks. They’re systems. Some rely entirely on digital access—keypads, apps, or biometrics. Others combine smart features with a traditional key cylinder. That distinction matters. Because you can’t “rekey” something that doesn’t use a physical key in the first place. Instead of pins and tumblers, fully digital locks rely on codes, permissions, and software-based control. So the way you reset access changes completely. Can Smart Locks Be Rekeyed? It Depends on the Type If your smart lock includes a physical key override, then yes—part of it can be rekeyed. The mechanical cylinder inside can be adjusted just like a traditional lock. A locksmith can change the key access without affecting the smart features. But if your smart lock is fully keyless, there’s nothing to rekey. In those cases, security is managed digitally. You simply delete old codes, reset access permissions, or perform a factory reset. No hardware changes required. Just a different kind of control. Why Digital Resetting Replaces Rekeying in Smart Systems With traditional locks, control comes from keys. With smart locks, control comes from access management. Instead of worrying about who has a physical copy, you manage: Who has a code When they can enter How long their access lasts If someone no longer needs entry, you don’t rekey. You remove them. That shift is what makes smart locks powerful—but also why people misunderstand how to secure them properly. When Rekeying Still Matters in a Smart Lock Setup Even if you use a smart lock, the physical key backup shouldn’t be ignored. That override exists for a reason. Power failures. Technical glitches. Dead batteries. In those moments, the mechanical key becomes your fallback. If that key has been copied, lost, or shared in the past, rekeying the cylinder is still essential. Because digital security means nothing if the physical backup is compromised. Should You Rekey or Replace a Smart Lock? Not every situation requires a full replacement. If your concern is access control, resetting codes or permissions is usually enough. If your concern is physical key security, rekeying the cylinder solves the problem. Replacement only becomes necessary when the lock is damaged, outdated, or no longer reliable. The mistake most people make is jumping straight to replacement—when a simple reset or rekey would have done the job. The Hidden Risk: Forgetting Old Access Points Whether it’s a traditional lock or a smart one, the real issue is often the same: Too many people have access. Old tenants. Previous owners. Contractors. Guests. With traditional locks, that risk lives in duplicated keys. With smart locks, it lives in forgotten codes and active permissions. If you don’t actively reset and review access, your lock—no matter how advanced—stops being secure. When to Call a Professional If you’re unsure whether your smart lock includes a rekeyable cylinder, or if it’s not functioning properly, it’s worth getting expert input. A locksmith can assess your setup, identify whether rekeying is possible, and ensure both your digital and physical security layers are aligned. Professionals like Brothers Locksmith often handle hybrid systems, where both smart features and traditional mechanisms need to work together seamlessly. Because real security isn’t about choosing one or the other. It’s about making sure every layer does its job. Final Thoughts Rekeying isn’t outdated. It’s just evolving. Traditional locks rely on it. Smart locks replace it with digital control. And hybrid systems use both. The key is understanding what kind of lock you actually have—and how it manages access. Because security isn’t about the label on your lock. It’s about who can still get in. And whether you’ve taken the time to change that.