5 Wacky Ways We May Soon Verify Our Identities Need to unlock your phone? Put it close enough to your skin so it can smell you.

Passwords are a pain. If we make them too simple, they're insecure and take seconds to crack. If we make them too complex, they're near impossible to remember. And it's not smart to use the same password across dozens of accounts -- contributing further to the inconvenience. Drawing a happy medium is incredibly difficult, and we often lack the time or willpower to sort it out.

According to password management company SplashData, the most commonly used passwords in 2015 were "123456" and "password." More creative ones include "welcome," "starwars" and, ironically, "letmein." We can almost hear hackers high-fiving each other in the distance.

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Luckily, two-factor authentication (2FA) is around to help. It requires more than just a password or PIN; users also need to clear a second challenge before gaining access. For example, when accessing online bank accounts, users are often required to enter a password, in addition to a one-time passcode (OTP) sent to their smartphone or tablet. As a result, stolen passwords become much less valuable -- unless they're reused with other services that don't have two-factor authentication -- and our accounts are more difficult to hack.

While two-factor authentication is a smart choice, it still leaves many to wonder when passwords and PINs will truly die and what viable methods will take their place. A popular option, and one already widely deployed across the globe, is biometric authentication. It can come in the form of fingerprint verification, facial recognition and retinal or iris scanning. However, it likely won't stop there.

Below are five wacky biometric methods we may one day use to verify our identities for personal or business use cases.

1. Edible, electronic capsules.

In 2015, Otsuka Pharmaceutical and Proteus Digital Health announced that the FDA was evaluating the world's first drug and device combination product. It combines Otsuka's ABILIFY tablets with Proteus' FDA-approved ingestible sensor to measure medication-taking patterns and physiological response. While the product is yet to be approved, it verifies the possibility that edible, electronic capsules are in the realm of possibility for medical use cases, as well as others.

For example, Proteus and Motorola entertained the idea of "vitamin authentication," or the process of swallowing a small pill containing a tiny computer chip powered by stomach acid, instead of battery acid. The electronic capsule would create an 18-bit ECG-like signal, turning us into passwords or fobs capable of granting us access to our smartphones or office buildings.

2. Body odor.

Machines could soon take jobs away from bloodhounds trained to identify people by their scents. According to researchers at the Polytechnic University of Madrid (UPM) and Ilía Sistemas SL, there are unique characteristics in each person's body odor that remain constant and can be used to determine identity. The biometric technique has an error rate of 15 percent in early stages of development, leaving room for improvement, but also showing promise that it could be a viable method with more fine-tuning.

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While it's bizarre to imagine our smart devices and electronics "sniffing" us to verify our identities, primary body odor is impossible to replicate and isn't masked by secondary odors (e.g., dietary, environmental) or tertiary odors (e.g., lotions, perfumes). So in the future, we should expect to cozy up a little more with our smart devices.

3. Electronic tattoos.

Technology company MC10 is reshaping the health care industry with its electronic skin patches designed to monitor patient vitals, such as heart rate, in real-time to improve human health. The patches, which are thinner than human hair, can bend, stretch and twist naturally with our bodies.

In addition, MC10 announced a recent partnership with custom products designer PCH to expand its application beyond the medical field. For instance, leveraging MC10's Wearable Interactive Stamp Platform (WiSP), L'Oréal debuted an electronic tattoo called My UV Patch at the 2016 Consumer Electronics Show. Other areas being explored include ticketed events, cashless payments and security, where the electronic tattoo could include our log-in credentials. MC10's WiSP technology could very well turn us into living, breathing passwords soon.

4. Brain waves.

In 2013, researchers at Japan's Tottori University published a journal on how distinctive alpha-beta brain wave patterns could determine human identities. For example, a car owner could use an EEG to record brain wave patterns that get stored in the car's biometric security system. When someone tries to turn the car on, the security system would continuously check the driver's brain waves for a correct match. If it's not a match, the car will not start.

More recently, researcher Blair Armstrong and his team at the Basque Center on Cognition, Brain and Language, published a journal detailing results from a study that signaled semantic memory is a cognitive system likely to vary uniquely across individuals and could serve as an accurate biometric authentication method. Achieving 97 percent accuracy proved promising for the technique, but given the inconvenient sensor applications required around the head, along with use of electrolytic gel, there's room for refinement before it is widely accepted. Hair gel users however, might welcome the existing method with open arms.

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5. Heartbeats.

Our hearts' electrical signals are unique and hard to replicate, making them great identifiers. Authentication company Nymi created a wearable device called Nymi Band that can identify users by their cardiac rhythms in real-time. With an embedded ECG sensor and an ability to communicate with smart technologies via Bluetooth, the wearable device can unlock phones, computers, vehicles and even office or hotel doors. In fact, Nymi is set to soon release a version suitable for enterprise employees, allowing them to seamlessly open corporate office doors, unlock corporate devices and access cloud services such as email -- either without a password altogether or using the wearable band as a second factor authentication method.

It's still not clear which biometric authentication methods will reign supreme in the long-term or if they will truly kill the password. However, the numerous achievements to date from researchers and technology companies alike are showing great promise. Whether the devices soak in our scent, tap into our thoughts or listen to our hearts beat, we'll undoubtedly get swept up in the romance and welcome a more secure and convenient way to integrate with our surroundings.