Chapter 5 Protecting Security of Assets Flashcards
Sensitive data
is any information that isn’t public or unclassified. It can include confidential, proprietary, protected, or any other type of data that an organization needs to protect due to its value to the organization, or to comply with existing laws and regulations.
Personally identifiable information (PII)
(1) any information that can be used to distinguish or trace an individual’s identity, such as name, social security number, date and place of birth, mother’s maiden name, or biometric records; and
(2) any other information that is linked or linkable to an individual, such as medical, educational, financial, and employment information.
Proprietary Data
refers to any data that helps an organization maintain a competitive edge. It could be software code it developed, technical plans for products, internal processes, intellectual property, or trade secrets. If competitors are able to access the proprietary data, it can seriously affect the primary mission of an organization.
data classification
identifies the value of the data to the organization and is critical to protect data confidentiality and integrity. The policy identifies classification labels used within the organization. It also identifies how data owners can determine the proper classification and how personnel should protect data based on its classification.
As an example, government data classifications include top secret, secret, confidential, and unclassified. Anything above unclassified is sensitive data, but clearly, these have different values. The U.S. government provides clear definitions for these classifications. As you read them, note that the wording of each definition is close except for a few key words. Top secret uses the phrase “exceptionally grave damage,” secret uses the phrase “serious damage,” and confidential uses “damage.”
Top Secret
“applied to information, the unauthorized disclosure of which reasonably could be expected to cause exceptionally grave damage to the national security that the original classification authority is able to identify or describe.”
Secret
“applied to information, the unauthorized disclosure of which reasonably could be expected to cause serious damage to the national security that the original classification authority is able to identify or describe.”
Confidential
“applied to information, the unauthorized disclosure of which reasonably could be expected to cause damage to the national security that the original classification authority is able to identify or describe.”
Unclassified
refers to any data that doesn’t meet one of the descriptions for top secret, secret, or confidential data. Within the United States, unclassified data is available to anyone, though it often requires individuals to request the information using procedures identified in the Freedom of Information Act (FOIA).
for official use only (FOUO) and sensitive but unclassified (SBU)
Documents with these designations have strict controls limiting their distribution. As an example, the U.S. Internal Revenue Service (IRS) uses SBU for individual tax records, limiting access to these records.
Confidential or Proprietary
label typically refers to the highest level of classified data. In this context, a data breach would cause exceptionally grave damage to the mission of the organization. As an example, attackers have repeatedly attacked Sony, stealing more than 100 terabytes of data including full-length versions of unreleased movies. These quickly showed up on file-sharing sites and security experts estimate that people downloaded these movies up to a million times. With pirated versions of the movies available, many people skipped seeing them when Sony ultimately released them. This directly affected their bottom line. The movies were proprietary and the organization might have considered it as exceptionally grave damage. In retrospect, they may choose to label movies as confidential or proprietary and use the strongest access controls to protect them.
Private
refers to data that should stay private within the organization but doesn’t meet the definition of confidential or proprietary data. In this context, a data breach would cause serious damage to the mission of the organization. Many organizations label PII and PHI data as private. It’s also common to label internal employee data and some financial data as private. As an example, the payroll department of a company would have access to payroll data, but this data is not available to regular employees.
Sensitive
is similar to confidential data. In this context, a data breach would cause damage to the mission of the organization. As an example, information technology (IT) personnel within an organization might have extensive data about the internal network including the layout, devices, operating systems, software, Internet Protocol (IP) addresses, and more. If attackers have easy access to this data, it makes it much easier for them to launch attacks. Management may decide they don’t want this information available to the public, so they might label it as sensitive.
Public
data is similar to unclassified data. It includes information posted in websites, brochures, or any other public source. Although an organization doesn’t protect the confidentiality of public data, it does take steps to protect its integrity. For example, anyone can view public data posted on a website. However, an organization doesn’t want attackers to modify this data so it takes steps to protect it.
Asset classifications
should match the data classifications. In other words, if a computer is processing top secret data, the computer should also be classified as a top secret asset. Similarly, if media such as internal or external drives holds top secret data, the media should also be classified as top secret.
It is common to use clear marking on the hardware assets so that personnel are reminded of data that can be processed or stored on the asset. For example, if a computer is used to process top secret data, the computer and the monitor will have clear and prominent labels reminding users of the classification of data that can be processed on the computer.
Confidential/Proprietary
highest level of protection for any data
Email and attachments must be encrypted with AES 256.
Email and attachments remain encrypted except when viewed.
Email can only be sent to recipients within the organization.
Email can only be opened and viewed by recipients (forwarded emails cannot be opened).
Attachments can be opened and viewed, but not saved.
Email content cannot be copied and pasted into other documents.
Email cannot be printed.
Private
examples include PII and PHI
Email and attachments must be encrypted with AES 256.
Email and attachments remain encrypted except when viewed.
Can only be sent to recipients within the organization.
Sensitive
lowest level of protection for classified data
Email and attachments must be encrypted with AES 256.
Public
Email and attachments can be sent in cleartext.
Data at Rest
is any data stored on media such as system hard drives, external USB drives, storage area networks (SANs), and backup tapes.
Data in Transit
(sometimes called data in motion) is any data transmitted over a network. This includes data transmitted over an internal network using wired or wireless methods and data transmitted over public networks such as the internet.
Data in Use
refers to data in memory or temporary storage buffers, while an application is using it. Because an application can’t process encrypted data, it must decrypt it in memory.
data breach
is any event in which an unauthorized entity can view or access sensitive data. If you pay attention to the news, you probably hear about data breaches quite often. Big breaches such as the Equifax breach of 2017 hit the mainstream news. Equifax reported that attackers stole personal data, including Social Security numbers, names, addresses, and birthdates, of approximately 143 million Americans.
Handling Sensitive Information and Assets
refers to the secure transportation of media through its lifetime. Personnel handle data differently based on its value and classification, and as you’d expect, highly classified information needs much greater protection. Even though this is common sense, people still make mistakes. Many times, people get accustomed to handling sensitive information and become lackadaisical with protecting it.
Storing Sensitive Data
Sensitive data should be stored in such a way that it is protected against any type of loss. The obvious protection is encryption. AES 256 provides strong encryption and there are many applications available to encrypt data with AES 256. Additionally, many operating systems include built-in capabilities to encrypt data at both the file level and the disk level.
Destroying Sensitive Data
When an organization no longer needs sensitive data, personnel should destroy it. Proper destruction ensures that it cannot fall into the wrong hands and result in unauthorized disclosure. Highly classified data requires different steps to destroy it than data classified at a lower level. An organization’s security policy or data policy should define the acceptable methods of destroying data based on the data’s classification. For example, an organization may require the complete destruction of media holding highly classified data, but allow personnel to use software tools to overwrite data files classified at a lower level.
NIST SP 800-88r1, “Guidelines for Media Sanitization,”
provides comprehensive details on different sanitization methods. Sanitization methods (such as clearing, purging, and destroying) ensure that data cannot be recovered by any means. When a computer is disposed of, sanitization includes ensuring that all nonvolatile memory has been removed or destroyed; the system doesn’t have compact discs (CDs)/digital versatile discs (DVDs) in any drive; and internal drives (hard drives and solid-state drives (SSDs) have been sanitized, removed, and/or destroyed. Sanitization can refer to the destruction of media or using a trusted method to purge classified data from the media without destroying it.
Eliminating Data Remanence
is the data that remains on media after the data was supposedly erased. It typically refers to data on a hard drive as residual magnetic flux. Using system tools to delete data generally leaves much of the data remaining on the media, and widely available tools can easily undelete it. Even when you use sophisticated tools to overwrite the media, traces of the original data may remain as less perceptible magnetic fields. This is similar to a ghost image that can remain on some TV and computer monitors if the same data is displayed for long periods of time. Forensics experts and attackers have tools they can use to retrieve this data even after it has been supposedly overwritten.
degausser
generates a heavy magnetic field, which realigns the magnetic fields in magnetic media such as traditional hard drives, magnetic tape, and floppy disk drives. Degaussers using power will reliably rewrite these magnetic fields and remove data remanence. However, they are only effective on magnetic media.
In contrast, SSDs use integrated circuitry instead of magnetic flux on spinning platters. Because of this, degaussing SSDs won’t remove data. However, even when using other methods to remove data from SSDs, data remnants often remain.Technicians commonly use degaussing methods to remove data from magnetic tapes with the goal of returning the tape to its original state. It is possible to degauss hard disks, but we don’t recommend it. Degaussing a hard disk will normally destroy the electronics used to access the data. However, you won’t have any assurance that all of the data on the disk has actually been destroyed. Someone could open the drive in a clean room and install the platters on a different drive to read the data. Degaussing does not affect optical CDs, DVDs, or SSDs.
Erasing
media is simply performing a delete operation against a file, a selection of files, or the entire media. In most cases, the deletion or removal process removes only the directory or catalog link to the data. The actual data remains on the drive. As new files are written to the media, the system eventually overwrites the erased data, but depending on the size of the drive, how much free space it has, and several other factors, the data may not be overwritten for months. Anyone can typically retrieve the data using widely available undelete tools.
Clearing, or overwriting
is a process of preparing media for reuse and ensuring that the cleared data cannot be recovered using traditional recovery tools. When media is cleared, unclassified data is written over all addressable locations on the media. One method writes a single character, or a specific bit pattern, over the entire media. A more thorough method writes a single character over the entire media, writes the character’s complement over the entire media, and finishes by writing random bits over the entire media. It repeats this in three separate passes, as shown in Figure 5.2. Although this sounds like the original data is lost forever, it is sometimes possible to retrieve some of the original data using sophisticated laboratory or forensics techniques. Additionally, some types of data storage don’t respond well to clearing techniques. For example, spare sectors on hard drives, sectors labeled as “bad,” and areas on many modern SSDs are not necessarily cleared and may still retain data.
Purging
is a more intense form of clearing that prepares media for reuse in less secure environments. It provides a level of assurance that the original data is not recoverable using any known methods. A purging process will repeat the clearing process multiple times and may combine it with another method such as degaussing to completely remove the data. Even though purging is intended to remove all data remnants, it isn’t always trusted. For example, the U.S. government doesn’t consider any purging method acceptable to purge top secret data. Media labeled top secret will always remain top secret until it is destroyed.
Destruction
is the final stage in the lifecycle of media and is the most secure method of sanitizing media. When destroying media it’s important to ensure that the media cannot be reused or repaired and that data cannot be extracted from the destroyed media. Methods of destruction include incineration, crushing, shredding, disintegration, and dissolving using caustic or acidic chemicals. Some organizations remove the platters in highly classified disk drives and destroy them separately.
