Passwords are our default method of securing digital privacy -- but they aren't very secure.

Criminals can pick up passwords easily, Wired's Matthew Honan writes, outlining how disturbingly simple it is. But it's not just the hackers that want to wipe out your checking account -- even police departments without NSA-style clearance can password crack. And in the wake of revelations about the government's widespread surveillance programs, according to CNET, federal authorities may be pushing for passwords.

It could be time to stop trusting passwords and switch over to another security system. But what could replace the venerable password?

Check out the list below for some authentication alternatives:

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  • Tattoos

    At All Things Digital's D11 conference in May, Motorola's Regina Dugan introduced several possible password alternatives -- one wearable. Dugan displayed <a href="" target="_blank">a temporary tattoo</a> containing "antennas and sensors" that would transmit a unique signal that could then be picked up as part of a passcode on a digital device. Like any temporary tattoo, it could be peeled off at any time and would last only up to a week.

  • Pills

    Dugan also introduced "<a href="" target="_blank">password pills</a>," small vitamin-like pills that users could eat at breakfast. The pills' contents -- activated by stomach acid -- would send out an "18-bit, ECG-like signal," similar to the kind used in an echocardiogram. The signal would work as secure authentication on digital devices, and <a href="" target="_blank">last about 24 hours </a> -- until the pill was passed out of the body.

  • RFID

    Technologist Amal Graafstra has been <a href="" target="_blank">injecting radio-frequency identification (RFID) chips into people's bodies</a> since summer of last year. When hit by a radio signal, the chip emits a signal of its own: Forbes describes it as "a unique identifier number that functions like a long, unguessable password." Hackers like Graafstra have programmed smartphones, computers and even car locks to recognize the signal given off by their implanted chips.

  • Gestures

    The technology now used in <a href="" target="_blank">Microsoft</a> and <a href="" target="_blank">Android's</a> picture passwords may be our best hope for replacing alphanumeric codes: after all, unlike tattoos, chips and pills, they're already on the market. But experts question the security of such gesture-based authentication; though taps and swipes may be <a href="" target="_blank">harder to guess</a> than strings of numbers and letters, telltale <a href="" target="_blank">smudges</a> and even <a href="" target="_blank">covert video recordings</a> could allow hackers to break in.

  • Faces

    Companies including Diebold and Finnish startup Uniqul have started experimenting with <a href="" target="_blank">facial recognition as authentication</a>. The good news? You're unlikely to forget your face. The bad news? <a href="" target="_blank">Currently</a> many facial recognition systems can be fooled by photographs.

  • Heartbeats

    Every person's heartbeat is unique -- so unique that no pattern of beats ever repeats twice. <a href="" target="_blank">This may make heartbeats perfect passwords</a>; Taiwanese scientists have recently devised a heartbeat-utilizing encryption scheme based on the mathematics of chaos theory. <a href="" target="_blank">Currently the Taiwanese system is still a prototype</a>, but researcher Chun-Liang Lin hopes to eventually "build the system into external hard drives and other devices that can be decrypted and encrypted simply by touching them."

  • Eye Movements

    Like heartbeats, eye movements are unique, hard to forge, and possibly excellent passwords. <a href="" target="_blank">Researchers at Texas State University - San Marco</a> are currently studying ways to turn eye movement into authentication.