Cell phones — particularly smartphones — are inherently bad for privacy. You've basically got a tracking device in your pocket, pinging off cell towers and locking onto GPS satellites. All the while, the handset's data connection ensures that tracking cookies, advertising IDs, and usage stats follow you around the internet.
So no, there's no such thing as a perfectly secure and truly private smartphone, let's get that out of the way now. But in the information age, you practically need a smartphone just to get by in society, so the question then becomes: Which phone manages to be the lesser of all the evils?
With critical vulnerabilities such as the Dirty COW exploit on Android and the Pegasus NSO hack on iOS, not to mention the FBI attempting to find a backdoor into practically every phone, that's a hard question to answer. So to find the most security-hardened devices, we tested the top smartphones on the market, looking for key factors like encryption strength, biometrics, VPN availability, and security patch time frames. Our research narrowed the list down to four great phones, so let's discuss how well each of these devices protects your privacy.
When it came to comparing our four finalist phones, these were the key differentiating factors for privacy and security:
- Biometrics: There are two schools of thought involving fingerprint scanners and other biometric unlocking methods. First, there's the idea that if your biometric identifiers were ever stolen, you wouldn't be able to change them like a password, making them permanently compromised. The second line of thinking is that if a security method is easier for the user, they'll be more likely to actually use it, in which case biometrics are better for security in general. So in the end, it's your call as to whether a fingerprint sensor is a good or bad thing, but note that having such hardware enables other security-related features such as LastPass' fingerprint login.
- Encryption: Each of these phones uses one of two types of encryption: file-based (FBE) or full disk (FDE). File-based encryption is the more effective method of the two, as it allows individual files to be locked with different keys, whereas full disk encryption uses only one key to lock the entire data partition. All four of these phones use the AES encryption standard, and while some use 128-bit keys to decrypt the data, others use more advanced 256-bit keys.
- Encryption Engine: This is more about performance than security, but some phones use hardware to handle the actual process of encrypting, while other phones do it with software. The iPhone 7, for instance, uses a dedicated hardware chip to handle encryption, which results in better read and write speeds than the Android phones in this list, which all use software-based encryption engines.
- Sandboxed User Accounts: If privacy is one of your top considerations, you may want to maintain separate user spaces on your phone — perhaps one for work, and another for your personal usage. If so, it's important that the data from each user account be truly separated (or "sandboxed"), and the Android phones in this list offer that feature.
- Restrict Ad Tracking: Phones that ship with Apple and Google services preinstalled use a system-wide advertising tracking ID to help marketing partners deliver targeted ads. This ID follows you around as you use apps and services on your phone, which is sketchy behavior when it comes to privacy. Apple allows you to restrict apps' abilities to view and use this identifier, while Google merely lets you to reset the ID and opt out of seeing personalized ads on Android devices.
- Always-On VPN: A virtual private network, or VPN, allows you to reroute internet traffic through an external server. A good VPN service will even let you encrypt all data traffic for increased anonymity. With Android devices, you can funnel all types of internet traffic through a VPN. With an iPhone, however, you can only use a VPN over Wi-Fi, unless you're willing to reset your device and enable "Supervised Mode" to get the VPN working on your mobile data connection.
- Block Internet Access for Apps: If you don't want apps "phoning home," the ability to block internet access on a per-app basis is a huge plus. With Android, this can be done by setting up a local VPN like Netguard, which takes a little extra work. With iOS, you can easily disable mobile data access for an app, however, it's not possible to restrict Wi-Fi connectivity.
- Calls & SMS Encrypted by Default: All phones in this list have access to Signal Private Messenger, which is an app that encrypts your calls and messages for added privacy. However, only the Blackphone 2 comes with this functionality by default.
- Anti-StingRay Detection: Government agencies have been known to use a fake cell tower device called a StingRay to intercept calls and SMS messages from a suspect in one of their ongoing investigations. The Blackphone 2 has a feature that notifies you when your phone might be connected to a StingRay, while the other phones in this list do not.
- Data Wipe After Failed Login: Some phones have a feature that triggers an automatic factory reset when someone attempts to enter your PIN or password too many times, if enabled. This is very effective when it comes to fending off intruders, as it makes brute-force password attacks all but impossible.
- LastPass: The popular password management service LastPass has varying degrees of functionality on each of these phones. Some of the devices allow you to log into the service using your fingerprint, others will auto-populate passwords into apps and websites for you, and the Pixel will let you do both.
- Stock Security Center App: If you're security-minded, it's good to have a centralized app that helps you handle all of your phone's security needs. The Blackberry PRIV and Blackphone offer such security center apps, which give you an overview of your phone's security health and allow you to easily tweak important security settings, among other things.
- OS CVEs: All phones in this list run either iOS or Android. In recent years, both of these operating systems have had numerous common vulnerabilities and exposures (CVEs) discovered, so it's important to keep track of exactly how vulnerable they are. In the past three years, CVEDetails has reported that 661 CVEs were found on Android, while 670 were found on iOS.
- Security Patch Timeframe: Blackphone promises that critical bugs will be patched within 72 hours. Like Google and the Pixel, Blackberry uses Android's recommended monthly security patch time frame, however, they will patch critical bugs faster than that if need be. Apple doesn't adhere to a specific time frame with its security patches, however, updates are generally issued within a month of critical bugs being found.
- Bug Bounties: Device manufacturers will usually offer a cash prize for anyone who can find glaring weaknesses in their phone's software, effectively crowd-sourcing the process of discovering and closing security loopholes. With a higher bounty, people will generally be more motivated to find these bugs. Some companies invite only trusted bug reporters to earn a bounty (depicted as "Closed" in the above chart), while others will let anybody report bugs and claim the bounty (shown as "Open" here).
Our first requirement in choosing these phones was that they all had to be available for sale in the United States. Secondly, for a phone to make this list, it had to be encrypted by default to ensure that your data is protected against external access.
Another requirement was that the phones all offered granular permission management, which allows you to revoke an app's permission to access certain features like your camera and microphone. Then, to ensure that your data remains safe even when your phone is lost or stolen, we only selected phones with remote lock and wipe capabilities.
From there, finalists were chosen based on how well the devices scored in the key comparison points above, and with that, the following phones rose to the top.
Startup manufacturer Silent Circle is a company that focuses on privacy and security in all of its products and services. Their second smartphone, the Blackphone 2, is powered by a security-focused fork of Android called Silent OS, which features privacy enhancements such as a security center that allows you to control what data apps can access (more on this later).
Silent Circle apparently subscribes to the school of thought that says biometrics are bad for security, as they've chosen not to include a fingerprint scanner on their Blackphone 2. This means that you won't be able to log into your LastPass account with your fingerprint, though, as an Android device, the Blackphone has the ability to auto-populate LastPass passwords into text fields and apps, so it's still a fairly easy process.
The Blackphone 2 uses 128-bit AES encryption, though it's of the full disk variety, meaning once the decryption key (your PIN or password) has been entered, the entire data partition is decrypted. This is still a very secure implementation, but encryption is handled entirely by software, so it can have an impact on device performance when compared to a handset like the iPhone, which uses a hardware encryption engine.
As an Android device, the Blackphone 2 has the ability to maintain separate user spaces. But to make things even better, Silent Circle has added a few additional undisclosed security measures to ensure that the data from each user account is completely inaccessible while logged into a different account. This feature would be particularly handy if you want to maintain a secondary, more secure user account that isn't logged into Google Services.
Speaking of Google Services, the Blackphone 2 will not let you limit the ability of apps to see and use Google's ad tracking identifier for your device, so you might want to periodically reset the ad tracking data in Settings -> Google. However, the Blackphone 2 gives you the option of installing an encrypted VPN app and using it on both Wi-Fi and cellular data, so the rest of your internet traffic can be completely anonymous. Additionally, you can use the same VPN feature to selectively block all internet access to individual apps.
Another major bonus when it comes to anonymity is the fact that each Blackphone 2 comes with a full year of Silent Circle's encrypted phone call and messaging service for free, so even your carrier won't be able to intercept your communications. On top of that, the Blackphone 2 has another awesome feature called CIDS (Cellular Intrusion Detection System), which notifies you when the device connects to a suspicious cell tower, in an attempt to protect your calls and text messages against StingRay surveillance devices used by government agencies.
The Blackphone 2 will automatically trigger a full data wipe after 10 failed login attempts, so you can rest assured that a brute-force password hack won't allow anyone to log into your phone. Then, to make things even more secure, Silent Circle has included a Security Center app that resides right on the home screen dock. The device automatically prevents apps from accessing sensitive information like your location or camera, and the Security Center app serves as the only way to reenable these permissions.
Silent Circle has their own bug bounty for the Blackphone that rewards up to $1,024 for any bugs found, and the program is open to the public. And as a sort of cherry on top, the Blackphone 2's single, most important security feature may very well be the fact that Silent Circle has promised to issue security updates within 72 hours of a critical bug being discovered, which tops all devices in this list by a considerable margin.
Even though the PRIV is over a year old, it's still BlackBerry's newest flagship device. The PRIV was BlackBerry's first Android phone, but they've since gone all-in on the Android ecosystem with two additional midrange phones in the DTEK50 and DTEK60. That hasn't changed BlackBerry's legendary security-first approach, as the PRIV has several privacy enhancements layered on top of its core Android code base — and another signature BlackBerry feature made the cut in the form of the PRIV's slide-out mechanical keyboard.
Like the Blackphone 2, the PRIV does not have a fingerprint scanner, which can be a positive or a negative depending on how you want to look at it. However, this does mean that you won't be able to log into LastPass with your fingerprint, but you the app can still auto-populate passwords for you.
The PRIV uses full disk encryption powered by a software-based encryption engine, which are two minor downsides relative to some other phones in this list, but still very strong security measures when compared to the rest of the smartphone market. To make the encryption even stronger, it's using 256-bit AES keys, which means there's 2 to the power of 256 possible combinations — a number so big that we don't even have a word for it.
With the help of its Android-powered operating system, the PRIV will let you create sandboxed user profiles that don't share any data between them, which is perfect for keeping your work and personal life separate. On top of that, Android allows the PRIV to use always-on VPN services to encrypt internet traffic on Wi-Fi and mobile data, as well as block internet access to individual apps. However, one downside to Android and its bundled Google Services is the fact that you cannot truly limit ad tracking like you can on the iPhone.
The PRIV will automatically wipe all user data when someone enters the wrong password or PIN ten times, which is a security measure BlackBerry has added on top of stock Android. And much like Silent Circle's approach with the Blackphone 2, BlackBerry has included a security center app called DTEK that will help you keep track of app permissions and inform you when there's a security issue that needs to be addressed.
BlackBerry is committed to Android's monthly security patch program, and they've stated that they will go a step further and issue faster updates if a critical security bug is ever found. The company also has a bug bounty program for its devices, but they don't disclose how much they're willing to pay when a programmer finds a security flaw in their software.
The iPhone 7, together with the iPhone 7 Plus, has helped Apple to reclaim the title of top smartphone maker in the world, as of Q4 2016. Top to bottom, it's an expertly crafted smartphone with benchmark scores that top the market (thanks to an insane spec sheet). However, it's the iPhone's security features that plant it firmly in this particular list.
The iPhone's Touch ID fingerprint scanner allows you to log into your phone in one tap, and the same feature works with numerous banking apps and similar services, such as LastPass. Depending on your line of thinking, you may view biometrics as a security risk, but you have to admit that Touch ID makes folks more likely to use longer, more secure passwords with their online services, since they can log into their accounts by touching a button instead typing out a complicated password.
The iPhone 7 uses AES 256-bit file-based encryption, which is as good as it gets with smartphones. This is powered by a dedicated hardware encryption engine, which contributes greatly to the device's top-notch read and write speeds.
Though the iPhone 7 does not offer a security center app, it does have a robust Privacy menu that allows you to restrict usage of the device's unique ad-tracking identifier. Enabling the "Limit Ad Tracking" option here will ensure that apps do not use your device's unique identifier in any way other than for "limited advertising purposes." This is different than the Android devices in this list, which will let you reset your ad-tracking ID and even opt out of being served targeted ads, but will not allow you to limit apps' abilities to view and use your unique ID.
Judging by public perception after the San Bernardino shooting investigation where Apple refused to create a backdoor for the FBI, as well as all of the above positives, you'd think the iPhone clearly outranks all Android devices in terms of security. But with feature phones like the PRIV and Blackphone that were purpose-built to appeal to privacy-minded users and the enterprise sector, there are a few key areas where Apple lags behind.
Apple has a bug bounty program for its iOS devices, as well as its iCloud service, and they offer more than any other manufacturer here for finding a critical issue (up to $200,000). But the program is not open to the public, so the pool of programmers working to find bugs is severely limited (just "a few dozen" invited researchers, according to Apple). It's worth noting, though, that other companies offer bug bounty programs for Apple devices, so that may help to offset this problem.
Other downsides are the lack of sandboxed user spaces, as well as the fact that you have to reset the device and enable "Supervised Mode" if you want to use an encrypted VPN service with your mobile data connection instead of just Wi-Fi.
Back on the positive side, you should know that Apple has an excellent track record when it comes to patching critical vulnerabilities found in iOS. It only took them two weeks to issue a fix for the Pegasus NSO hack, and just over a month to plug up the 911 bug in iOS 10, so backdoors are closed almost as quickly as they're found.
On a final note, these same privacy features apply to all of Apple's current-generation smartphones. We're recommending the iPhone 7 here as it offers the best balance of specs and pricing, but you can go with an iPhone 7 Plus if you like a bigger phone, or an iPhone SE if you want to save some extra money while sacrificing a few bonus specs like screen size.
The Pixel and its bigger brother, the Pixel XL, are the first phones made by Google, yet they've already been an all-around success in terms of sales and general reception. As the only Android device in this list that wasn't a purpose-built security "feature phone," the Pixel still garners consideration in large part due to two factors that differentiate it from the rest of the Android pack: timely updates directly from Google, and file-based encryption. Couple that with the phone's top-notch specs, and it's worth a consideration on multiple levels.
The Pixel's fingerprint scanner, dubbed Pixel Imprint, works much the same as Apple's Touch ID in that it allows you to unlock your phone easily and even log into apps and services. Combined with Android's ability to let the LastPass app auto-populate your complicated passwords, this means that the Pixel is the only phone in this list that will let you use LastPass to log into apps and websites by simply touching the fingerprint scanner.
The Pixel uses a software-based encryption engine, which has been known to slow down read and write speeds on some devices. However, it's one of the only Android phones to date that uses file-based encryption, which gives the device an extra layer of security to go along with its 256-bit AES decryption key.
The Pixel will let you create sandboxed user spaces that do not share any personal data, so you can keep your work and personal life separate. In addition to that, you can set up a system-wide VPN to encrypt traffic on Wi-Fi and mobile data connections alike, and this same feature can be used to block apps from accessing the internet altogether.
As for downsides, the Pixel does not allow you to restrict apps' access to your device's unique advertising identifier, so you'd be well served to periodically reset this ID number. There's also no security center app, so you'll have to dig around in Settings to manage app permissions and other privacy options. Finally, the Pixel does not automatically wipe data after too many failed logins, which leaves the device susceptible to a brute-force password or PIN attack.
But on the bright side, Google has perhaps the best bug bounty program of all the manufacturers in this list. They'll offer up to $50,000 for critical bugs found, and the program is open to the public, so there should always be plenty of folks scouring the Pixel's code base for security loopholes. And as Google is the primary maintainer of the entire Android operating system, the Pixel has strong software support, as it gets security updates on a monthly basis.
The Blackphone 2 is genuinely a cut above the rest when it comes to privacy and security. With standout features such as its StingRay detection, as well as the free year of encrypted calls and messages, you can just tell that this device was built from the ground up with one thing in mind — privacy.
Having said that, you may not need (or even want) these over-the-top privacy features, and perhaps a solidly-secure phone with top-notch specs is more up your alley. If that's the case, the BlackBerry PRIV ticks a lot of boxes in terms of both hardware and security, while the iPhone and Pixel both knock it out of the park when it comes to specs, and simultaneously offer solid security options.