FileVault in the System Preferences under Security
|Other names||Disk encryption software|
May 08, 2020 Related: 6 Best All In One Security Software for Mac. Entropy has been designed specifically for Mac to archive files on Mac. This dedicated Mac unzipper app supports OS X specific technologies like extended file attributes and resource forks, and also directly reads and writes archives. Best next generation encryption app for macOS und iOS. SimpleumSafe – made in Germany. Easy-to-use encryption software for Mac and iOS. Keep personal or business data and folders password-protected. Encrypt files to be protected in the event of a unauthorized access. Encrypto is a free, easy-to-use app that lets you encrypt files with AES-256 encryption and then send them to friends or coworkers. It works on both Mac and Windows, so you can send encrypted files without worrying whether the other person can open it or not. Protect Files with AES-256 Encryption T. Best encryption software for Mac OS X Many people are looking for effective methods to keep the sensitive files stored on their Macs away from prying eyes. Some try hiding their files, others store them on portable devices that they carry around, but encryption is undoubtedly the safest solution, especially if you're using the right tools.
FileVault is a disk encryption program in Mac OS X 10.3 (2003) and later. It performs on-the-fly encryption with volumes on Mac computers.
Versions and key features
FileVault was introduced with Mac OS X Panther (10.3), and could only be applied to a user's home directory, not the startup volume. The operating system uses an encrypted sparse disk image (a large single file) to present a volume for the home directory. Mac OS X Leopard and Mac OS X Snow Leopard use more modern sparse bundle disk images which spread the data over 8 MB files (called bands) within a bundle. Apple refers to this original iteration of FileVault as legacy FileVault.
Mac OS X Lion (2011) and newer offer FileVault 2, which is a significant redesign. This encrypts the entire OS X startup volume and typically includes the home directory, abandoning the disk image approach. For this approach to disk encryption, authorised users' information is loaded from a separate non-encrypted boot volume (partition/slice type Apple_Boot).
The original version of FileVault was added in Mac OS X Panther to encrypt a user's home directory.
Master passwords and recovery keys
When FileVault is enabled the system invites the user to create a master password for the computer. If a user password is forgotten, the master password or recovery key may be used to decrypt the files instead.
Migration of FileVault home directories is subject to two limitations:
- there must be no prior migration to the target computer
- the target must have no existing user accounts.
If Migration Assistant has already been used or if there are user accounts on the target:
- before migration, FileVault must be disabled at the source.
If transferring FileVault data from a previous Mac that uses 10.4 using the built-in utility to move data to a new machine, the data continues to be stored in the old sparse image format, and the user must turn FileVault off and then on again to re-encrypt in the new sparse bundle format.
Instead of using FileVault to encrypt a user's home directory, using Disk Utility a user can create an encrypted disk image themselves and store any subset of their home directory in there (for example, ~/Documents/private). This encrypted image behaves similar to a Filevault encrypted home directory, but is under the user's maintenance.
Encrypting only a part of a user's home directory might be problematic when applications need access to the encrypted files, which will not be available until the user mounts the encrypted image. This can be mitigated to a certain extent by making symbolic links for these specific files.
Limitations and issues
- These limitations apply to versions of Mac OS X prior to v10.7 only.
Without Mac OS X Server, Time Machine will back up a FileVault home directory only while the user is logged out. In such cases, Time Machine is limited to backing up the home directory in its entirety. Using Mac OS X Server as a Time Machine destination, backups of FileVault home directories occur while users are logged in.
Because FileVault restricts the ways in which other users' processes can access the user's content, some third party backup solutions can back up the contents of a user's FileVault home directory only if other parts of the computer (including other users' home directories) are excluded.
Several shortcomings were identified in Legacy FileVault. Its security can be broken by cracking either 1024-bit RSA or 3DES-EDE.
Legacy FileVault used the CBC mode of operation (see disk encryption theory); FileVault 2 uses stronger XTS-AESW mode. Another issue is storage of keys in the macOS 'safe sleep' mode. A study published in 2008 found data remanence in dynamic random-access memory (DRAM), with data retention of seconds to minutes at room temperature and much longer times when memory chips were cooled to low temperature. The study authors were able to use a cold boot attack to recover cryptographic keys for several popular disk encryption systems, including FileVault, by taking advantage of redundancy in the way keys are stored after they have been expanded for efficient use, such as in key scheduling. The authors recommend that computers be powered down, rather than be left in a 'sleep' state, when not in physical control by the owner.
Early versions of FileVault automatically stored the user's passphrase in the system keychain, requiring the user to notice and manually disable this security hole.
In 2006, following a talk at the 23rd Chaos Communication Congress titled Unlocking FileVault: An Analysis of Apple's Encrypted Disk Storage System, Jacob Appelbaum & Ralf-Philipp Weinmann released VileFault which decrypts encrypted Mac OS X disk image files.
A free space wipe using Disk Utility left a large portion of previously deleted file remnants intact. Similarly, FileVault compact operations only wiped small parts of previously deleted data.
FileVault uses the user's login password as the encryption pass phrase. It uses the AES-XTS mode of AES with 128 bit blocks and a 256 bit key to encrypt the disk, as recommended by NIST. Only unlock-enabled users can start or unlock the drive. Once unlocked, other users may also use the computer until it is shut down.
The I/O performance penalty for using FileVault 2 was found to be in the order of around 3% when using CPUs with the AES instruction set, such as the Intel Core i and MacOS 10.10.3. Performance deterioration will be larger for CPUs without this instruction set, such as older Core CPUs.
Master passwords and recovery keys
When FileVault 2 is enabled while the system is running, the system creates and displays a recovery key for the computer, and optionally offers the user to store the key with Apple. The 120 bit recovery key is encoded with all letters and numbers 1 through 9, and read from /dev/random, and therefore relies on the security of the PRNG used in macOS. During a cryptanalysis in 2012, this mechanism was found safe.
Changing the recovery key is not possible without re-encrypting the File Vault volume.
Users who use FileVault 2 in OS X 10.9 and above can validate their key correctly works after encryption by running sudo fdesetup validaterecovery in Terminal after encryption has finished. The key must be in form xxxx-xxxx-xxxx-xxxx-xxxx-xxxx and will return true if correct.
Starting the OS with FileVault 2 without a user account
If a volume to be used for startup is erased and encrypted before clean installation of OS X 10.7.4 or 10.8:
- there is a password for the volume
- the clean system will immediately behave as if FileVault was enabled after installation
- there is no recovery key, no option to store the key with Apple (but the system will behave as if a key was created)
- when the computer is started, Disk Password will appear at the EfiLoginUI – this may be used to unlock the volume and start the system
- the running system will present the traditional login window.
Apple describes this type of approach as Disk Password—based DEK.
- ^'Apple Previews Mac OS X 'Panther''. Apple Press Info. Apple. June 23, 2003. Retrieved January 21, 2013.
- ^ScottW (November 5, 2007). 'Live FileVault and Sparse Bundle Backups in Leopard'. macosx.com. Archived from the original on October 29, 2013. Retrieved January 21, 2013.
- ^ abcdApple Inc (August 9, 2012). 'OS X: About FileVault 2'. Apple Inc. Retrieved September 5, 2012.
- ^Apple Inc (August 17, 2012). 'Best Practices for Deploying FileVault 2'(PDF). Apple Inc. p. 40. Archived from the original(PDF) on August 22, 2017. Retrieved September 5, 2012.
- ^'Archived - Mac OS X 10.3, 10.4: Transferring data with Setup Assistant / Migration Assistant FAQ'. Apple support. Apple. Retrieved January 21, 2013.
- ^'Using Encrypted Disks'. CrashPlan PROe support. CrashPlan PROe. Retrieved January 21, 2013.
- ^'Using CrashPlan with FileVault'. CrashPlan support. CrashPlan. Retrieved January 21, 2013.
- ^Jacob Appelbaum, Ralf-Philipp Weinmann (December 29, 2006). 'Unlocking FileVault: An Analysis of Apple's disk encryption'(PDF). Retrieved March 31, 2007.Cite journal requires
- ^J. Alex Halderman; et al. (February 2008). 'Lest We Remember: Cold Boot Attacks on Encryption Keys'(PDF). Archived from the original(PDF) on May 14, 2008.Cite journal requires
- ^'Unlocking FileVault: An analysis of Apple's disk encryption system'(PDF).
- ^'File Vault's Dirty Little Secrets'.
- ^ abApple, Inc (August 17, 2012). 'Best Practices for Deploying FileVault 2'(PDF). Apple, Inc. p. 28. Archived from the original(PDF) on August 22, 2017. Retrieved September 5, 2012.
- ^Dworkin, Morris (January 2010). 'Recommendation for Block Cipher Modes of Operation: The XTS-AES Mode for Confidentiality on Storage Devices'(PDF). NIST Special Publication (800–3E).
- ^'Tech ARP - How Fast is the 512 GB PCIe X4 SSD in the 2015 MacBook Pro?'.
- ^Choudary, Omar; Felix Grobert; Joachim Metz (July 2012). 'Infiltrate the Vault: Security Analysis and Decryption of Lion Full Disk Encryption'. Retrieved January 19, 2013.Cite journal requires
- ^'fdesetup(8) Mac OS X Manual Page'. Apple. August 21, 2013. Retrieved August 9, 2014.
Encryption is a difficult concept to grasp, but it's a necessary part of protecting your business's sensitive data. At a basic level, encryption is the process of scrambling text (called ciphertext) to render it unreadable to unauthorized users. You can encrypt individual files, folders, volumes or entire disks within a computer, as well as USB flash drives and files stored in the cloud.
Why is encryption important?
The purpose of file and disk encryption is to protect data stored on a computer or network storage system. All organizations, including small and midsize businesses (SMBs), that collect personally identifiable information (PII) like names, birthdates, Social Security numbers and financial information must secure that information. An organization can be sued if a computer containing PII is stolen and the information is leaked or shared.
If a laptop is lost or stolen and the files or disk aren't encrypted, a thief can easily steal the information, so it's a good practice to encrypt your sensitive data, if not your entire hard drive. The thief doesn't even need to know the sign-on password to access the files – it's easy to boot a computer from a USB thumb drive and then access the disks within the computer.
Disk encryption doesn't protect a computer entirely. A hacker can still access the computer over an insecure network connection, or a user can click a malicious link in an email and infect the computer with malware that steals usernames and passwords. Those types of attacks require additional security controls, like anti-malware software, firewalls and awareness training. However, encrypting a computer's files or the entire disk greatly reduces the risk of data theft.
Encryption 101: How does it work?
When making decisions regarding encryption, it's important to have a basic grasp on how encryption works. Encryption is a digital form of cryptography, which uses mathematical algorithms to scramble messages, leaving only individuals who possess the sender's cipher or key able to decode the message.
There are two main methods of encryption: symmetric encryption, which involves securing data with a single private key, and asymmetric encryption, which uses a combination of multiple keys that are both public and private.
The most common form of symmetric encryption is Advanced Encryption Standard (AES), which is the U.S. government standard for encryption. Data in hexadecimal form is scrambled multiple times and utilizes 128-bit, 192-bit or 256-bit keys to unlock, the latter being the strongest. Keys can be substituted with passwords that we create, making the password the only direct way to decrypt the data. This method is best suited for encrypting files and drives. The only weak spot is the password itself, which hackers may break if it's weak. They're unlikely to strong-arm their way into the data through encryption. Keep in mind that, though 128-bit AES is a strong encryption key, most government regulations require the stronger 256-bit AES to meet certain standards.
Asymmetric encryption is used for sending secured messages and other data between two individuals. On messaging platforms, such as most email services, all users have a public key and a private key. The public key acts as type of address and method for the sender to encrypt their message. That message is further encrypted with the sender's private key. The receiver can then use the sender's public key to verify the message sender and then decrypt the message with their own private key. A hacker who intercepts the message will be unable to view its contents without the receiver's private key.
Types of computer encryption
Individual file and folder encryption does just that – encrypts only the specific items that you tell it to. This method is acceptable if relatively few business documents are stored on a computer, and it's better than no encryption at all.
One step up is volume encryption, which creates a container of sorts that's fully encrypted. All files and folders created in or saved to that container are encrypted.
Full-disk or whole-disk encryption is the most complete form of computer encryption. It's transparent to users and doesn't require them to save files to a special place on the disk – all files, folders and volumes are encrypted.
With full-disk encryption, you must provide an encryption passcode or have the computer read an encryption key (a random string of letters and numbers) from a USB device when powering on your computer. This action unlocks the files so you can use them normally.
Built-in encryption programs
Strong encryption is built into modern versions of the Windows and OS X operating systems, and it's available for some Linux distributions as well.
Microsoft BitLocker is a disk encryption tool included in Windows 7 (Enterprise and Ultimate) and the Pro and Enterprise editions of Windows 8.1 and Windows 10. It's designed to work with a Trusted Platform Module chip in your computer, which stores your disk encryption key. It's possible to enable BitLocker even without the chip, but a few settings must be configured within the operating system, which requires administrative privileges.
To enable BitLocker, open Windows Explorer or File Explorer and right-click on Drive C. If your version of Windows supports BitLocker, the menu will display a 'Turn on BitLocker' option, which you can click to enable the program.
When you enable BitLocker, Microsoft prompts you to save a copy of your recovery key. This is an important step because you need the recovery key to unlock your disk. Without the key, neither you nor anyone else cannot access the data. You can print the key or save it to your Microsoft account or a file. BitLocker also lets you require a PIN at startup.
Apple FileVault provides encryption for computers running Mac OS X. When enabling encryption, FileVault prompts you to store the disk encryption recovery key in your iCloud account, but you can choose to write it down instead.
For Linux, you typically encrypt the disk during installation of the operating system, using a tool such as dm-crypt. However, third-party tools are also available for post-installation encryption.
Third-party encryption programs
TrueCrypt used to be one of the most popular open-source disk encryption software programs, but its developers stopped maintaining it in 2014. Security experts are still torn on whether it's safe to use. To be on the safe side, stick with a product that's regularly tested and updated. These are a few open-source products that are well regarded:
Mac Os Encrypt File
- VeraCrypt is free software that runs on Windows, Mac OS X and Linux. It frequently gets the highest ratings from users and third-party testers.
- AxCrypt is an easy-to-use encryption program with free and premium versions. It has a password manager and collaboration feature for sharing encrypted data with others.
- Gpg4win uses military-grade security to encrypt and digitally sign files and emails.
Many anti-malware vendors, such as Symantec, Kaspersky, Sophos and ESET, include encryption in their security suites or sell it as a stand-alone product.
USB drives should also be encrypted, because when you copy files from an encrypted disk to a USB drive, the files can be automatically decrypted.
'It's important to educate employees that once they send a file via email or copy it to a USB thumb drive, that data is no longer protected by that encryption,' said Joe Siegrist, vice president and general manager of LogMeIn's LastPass password management software.
To ensure files on a USB device are encrypted, use software like Microsoft BitLocker To Go or open-source software, or purchase USB drives that come with encryption, such as IronKey, SanDisk and Kanguru.
Best practices for computer encryption
Before enabling encryption on your computer, back up your data files and create an image backup, which is a replica of all the contents of your disk. You should also ensure that you have the operating system's installation media and create an emergency boot disk on removable media.
Going forward, back up your computer regularly. An encrypted disk that crashes or becomes corrupt can result in files being lost forever. If you have a current backup, you can be up and running fairly quickly.
When creating a passcode or PIN, use random numbers and letters, and memorize it. The longer and more complex, the better, but not so complex that you can't remember it. Consider putting two phrases together, like short verses from two songs you like. Use only the first letter of each word, and substitute some characters, such as a zero for an O and a 3 or pound sign (#) for an E. Use mixed capitalization as well. More tips for creating a strong password can be found in this Business News Daily article.
Keep a written copy of your PIN or passcode and your encryption key (if separate) in a safe place, in case you forget them. If you enable full-disk encryption and forget your passcode, you won't be able to access your computer, and neither can anyone else, including IT personnel or even a data recovery service, Siegrist said.
If you use Wi-Fi, use Wi-Fi Protected Access 2 (WPA2), which is a form of encryption for protecting wireless connections. Don't use Wired Equivalent Privacy (WEP), which isn't safe under any circumstances.
Finally, use a virtual private network to access the office network from a laptop or other mobile device when working remotely. A VPN creates a secure tunnel over the internet, encrypting all data that you send and receive during that session.
Remember, computer encryption is only one part of a complete security plan for protecting computers and confidential data. It's a necessary security control for organizations that handle confidential data, and it should be enabled on any device that could fall into the wrong hands. Visit our small business cybersecurity guide for more tips and advice.
Encryption For Mac
Additional reporting by Kim Lindros.