Supplementing Passwords

Why aren't passwords sufficient?

Passwords are beneficial as a first layer of protection, but they are susceptible to being guessed or intercepted by attackers. You can increase the effectiveness of your passwords by using tactics such as avoiding passwords that are based on personal information or words found in the dictionary; using a combination of numbers, special characters, and lowercase and capital letters; and not sharing your passwords with anyone else. However, despite your best attempts, an attacker may be able to obtain your password. If there are no additional security measures in place, the attacker may be able to access your personal, financial, or medical information.

What additional levels of security are being used?

Many organizations are beginning to use other forms of verification in addition to passwords. The following practices are becoming more and more common:

• two-factor authentication - With two-factor authentication, you use your password in conjunction with an additional piece of information. An attacker who has managed to obtain your password can't do anything without the second component. The theory is similar to requiring two forms of identification or two keys to open a safe deposit box. However, in this case, the second component is commonly a "one use" password that is voided as soon as you use it. Even if an attacker is able to intercept the exchange, he or she will still not be able to gain access because that specific combination will not be valid again.
• personal web certificates - Unlike the certificates used to identify web sites, personal web certificates are used to identify individual users. A web site that uses personal web certificates relies on these certificates and the authentication process of the corresponding public/private keys to verify that you are who you claim to be. Because information identifying you is embedded within the certificate, an additional password is unnecessary. However, you should have a password to protect your private key so that attackers can't gain access to your key and represent themselves as you. This process is similar to two-factor authentication, but it differs because the password protecting your private key is used to decrypt the information on your computer and is never sent over the network.

What if you lose your password or certificate?

You may find yourself in a situation where you've forgotten your password or you've reformatted your computer and lost your personal web certificate. Most organizations have specific procedures for giving you access to your information in these situations. In the case of certificates, you may need to request that the organization issue you a new one. In the case of passwords, you may just need a reminder. No matter what happened, the organization needs a way to verify your identity. To do this, many organizations rely on "secret questions."

When you open a new account (email, credit card, etc.), some organizations will prompt you to provide them with the answer to a question. They may ask you this question if you contact them about forgetting your password or you request information about your account over the phone. If your answer matches the answer they have on file, they will assume that they are actually communicating with you. While the theory behind the secret question has merit, the questions commonly used ask for personal information such as mother's maiden name, social security number, date of birth, or pet's name. Because so much personal information is now available online or through other public sources, attackers may be able to discover the answers to these questions without much effort.

Realize that the secret question is really just an additional password—when setting it up, you don't have to supply the actual information as your answer. In fact, when you are asked in advance to provide an answer to this type of question that will be used to confirm your identity, dishonesty may be the best policy. Choose your answer as you would choose any other good password, store it in a secure location, and don't share it with other people.

While the additional security practices do offer you more protection than a password alone, there is no guarantee that they are completely effective. Attackers may still be able to access your information, but increasing the level of security does make it more difficult. Be aware of these practices when choosing a bank, credit card company, or other organization that will have access to your personal information. Don't be afraid to ask what kind of security practices the organization uses.

Effectively Erasing Files

Where do deleted files go?

When you delete a file, depending on your operating system and your settings, it may be transferred to your trash or recycle bin. This "holding area" essentially protects you from yourself—if you accidentally delete a file, you can easily restore it. However, you may have experienced the panic that results from emptying the trash bin prematurely or having a file seem to disappear on its own. The good news is that even though it may be difficult to locate, the file is probably still somewhere on your machine. The bad news is that even though you think you've deleted a file, an attacker or other unauthorized person may be able to retrieve it.

What are the risks?

Think of the information you have saved on your computer. Is there banking or credit card account information? Tax returns? Passwords? Medical or other personal data? Personal photos? Sensitive corporate information? How much would someone be able to find out about you or your company by looking through your computer files?

Depending on what kind of information an attacker can find, he or she may be able to use it maliciously. You may become a victim of identity theft. Another possibility is that the information could be used in a social engineering attack. Attackers may use information they find about you or an organization you're affiliated with to appear to be legitimate and gain access to sensitive data.

Can you erase files by reformatting?

Reformatting your hard drive, CD, or DVD may superficially delete the files, but the information is still buried somewhere. Unless those areas of the disk are effectively overwritten with new content, it is still possible that knowledgeable attackers may be able to access the information.

How can you be sure that your information is completely erased?

Some people use extreme measures to make sure their information is destroyed, but these measures can be dangerous and may not be completely successful. Your best option is to investigate software programs and hardware devices that claim to erase your hard drive, CD, or DVD. Even so, these programs and devices have varying levels of effectiveness. When choosing a software program to perform this task, look for the following characteristics:

• "Secure Erase" is performed - Secure Erase is a standard in modern hard drives. If you select a program that runs the Secure Erase command, it will erase data by overwriting all areas of the hard drive, even areas that are not being used.
• data is written multiple times - It is important to make sure that not only is the information erased, but new data is written over it. By adding multiple layers of data, the program makes it difficult for an attacker to "peel away" the new layer. Three to seven passes is fairly standard and should be sufficient.
• random data is used - Using random data instead of easily identifiable patterns makes it harder for attackers to determine the pattern and discover the original information underneath.
• zeros are used in the final layer - Regardless of how many times the program overwrites the data, look for programs that use all zeros in the last layer. This adds an additional level of security.

While many of these programs assume that you want to erase an entire disk, there are programs that give you the option to erase and overwrite individual files.

An effective way to ruin a CD or DVD is to wrap it in a paper towel and shatter it. However, there are also hardware devices that erase CDs or DVDs by destroying their surface. Some of these devices actually shred the media itself, while others puncture the writable surface with a pattern of holes. Many paper shredders will also shred CDs and DVDs. If you decide to use one of these devices, compare the various features and prices to determine which option best suits your needs.

Understanding Encryption

What is encryption?

In very basic terms, encryption is a way to send a message in code. The only person who can decode the message is the person with the correct key; to anyone else, the message looks like a random series of letters, numbers, and characters.

Encryption is especially important if you are trying to send sensitive information that other people should not be able to access. Because email messages are sent over the internet and might be intercepted by an attacker, it is important to add an additional layer of security to sensitive information.

How is it different from digital signatures?

Like digital signatures, public-key encryption utilizes software such as PGP, converts information with mathematical algorithms, and relies on public and private keys, but there are differences:

• The purpose of encryption is confidentiality—concealing the content of the message by translating it into a code. The purpose of digital signatures is integrity and authenticity—verifying the sender of a message and indicating that the content has not been changed. Although encryption and digital signatures can be used independently, you can also sign an encrypted message.
• When you sign a message, you use your private key, and anybody who has your public key can verify that the signature is valid. When you encrypt a message, you use the public key for the person you're sending it to, and his or her private key is used to decrypt the message. Because people should keep their private keys confidential and should protect them with passwords, the intended recipient should be the only one who is able to view the information.

How does encryption work?

1. Obtain the public key for the person you want to be able to read the information. If you get the key from a public key ring, contact the person directly to confirm that the series of letters and numbers associated with the key is the correct fingerprint.
2. Encrypt the email message using their public key. Most email clients have a feature to easily perform this task.
3. When the person receives the message, he or she will be able to decrypt it.

How to Protect Your Privacy?

How do you know if your privacy is being protected?

• Privacy policy - Before submitting your name, email address, or other personal information on a website, look for the site's privacy policy. This policy should state how the information will be used and whether or not the information will be distributed to other organizations. Companies sometimes share information with partner vendors who offer related products or may offer options to subscribe to particular mailing lists. Look for indications that you are being added to mailing lists by default—failing to deselect those options may lead to unwanted spam. If you cannot find a privacy policy on a website, consider contacting the company to inquire about the policy before you submit personal information, or find an alternate site. Privacy policies sometimes change, so you may want to review them periodically.
• Evidence that your information is being encrypted - To protect attackers from hijacking your information, any personal information submitted online should be encrypted so that it can only be read by the appropriate recipient. Many sites use SSL, or secure sockets layer, to encrypt information. Indications that your information will be encrypted include a URL that begins with "https:" instead of "http:" and a lock icon in the bottom right corner of the window. Some sites also indicate whether the data is encrypted when it is stored. If data is encrypted in transit but stored insecurely, an attacker who is able to break into the vendor's system could access your personal information.

What additional steps can you take to protect your privacy?

• Do business with credible companies - Before supplying any information online, consider the answers to the following questions: do you trust the business? is it an established organization with a credible reputation? does the information on the site suggest that there is a concern for the privacy of user information? is there legitimate contact information provided?
• Do not use your primary email address in online submissions - Submitting your email address could result in spam. If you do not want your primary email account flooded with unwanted messages, consider opening an additional email account for use online. Make sure to log in to the account on a regular basis in case the vendor sends information about changes to policies.
• Avoid submitting credit card information online - Some companies offer a phone number you can use to provide your credit card information. Although this does not guarantee that the information will not be compromised, it eliminates the possibility that attackers will be able to hijack it during the submission process.
• Devote one credit card to online purchases - To minimize the potential damage of an attacker gaining access to your credit card information, consider opening a credit card account for use only online. Keep a minimum credit line on the account to limit the amount of charges an attacker can accumulate.
• Avoid using debit cards for online purchases - Credit cards usually offer some protection against identity theft and may limit the monetary amount you will be responsible for paying. Debit cards, however, do not offer that protection. Because the charges are immediately deducted from your account, an attacker who obtains your account information may empty your bank account before you even realize it.
• Take advantage of options to limit exposure of private information - Default options on certain websites may be chosen for convenience, not for security. For example, avoid allowing a website to remember your password. If your password is stored, your profile and any account information you have provided on that site is readily available if an attacker gains access to your computer. Also, evaluate your settings on websites used for social networking. The nature of those sites is to share information, but you can restrict access to certain information so that you limit who can see what.

How Does Your Information Spread Across the Internet?

What information is collected?

When you visit a website, a certain amount of information is automatically sent to the site. This information may include the following:

• IP address - Each computer on the internet is assigned a specific, unique IP (internet protocol) address. Your computer may have a static IP address or a dynamic IP address. If you have a static IP address, it never changes. However, some ISPs own a block of addresses and assign an open one each time you connect to the internet—this is a dynamic IP address. 
• domain name - The internet is divided into domains, and every user's account is associated with one of those domains. You can identify the domain by looking at the end of URL; for example, .edu indicates an educational institution, .gov indicates a US government agency, .org refers to organization, and .com is for commercial use. Many countries also have specific domain names. 
• software details - It may be possible for an organization to determine which browser, including the version, that you used to access its site. The organization may also be able to determine what operating system your computer is running.
• page visits - Information about which pages you visited, how long you stayed on a given page, and whether you came to the site from a search engine is often available to the organization operating the website.

If a website uses cookies, the organization may be able to collect even more information, such as your browsing patterns, which include other sites you've visited. If the site you're visiting is malicious, files on your computer, as well as passwords stored in the temporary memory, may be at risk.

How is this information used?

Generally, organizations use the information that is gathered automatically for legitimate purposes, such as generating statistics about their sites. By analyzing the statistics, the organizations can better understand the popularity of the site and which areas of content are being accessed the most. They may be able to use this information to modify the site to better support the behavior of the people visiting it.

Another way to apply information gathered about users is marketing. If the site uses cookies to determine other sites or pages you have visited, it may use this information to advertise certain products. The products may be on the same site or may be offered by partner sites.

However, some sites may collect your information for malicious purposes. If attackers are able to access files, passwords, or personal information on your computer, they may be able to use this data to their advantage. The attackers may be able to steal your identity, using and abusing your personal information for financial gain. A common practice is for attackers to use this type of information once or twice, then sell or trade it to other people. The attackers profit from the sale or trade, and increasing the number of transactions makes it more difficult to trace any activity back to them. The attackers may also alter the security settings on your computer so that they can access and use your computer for other malicious activity.

Are you exposing any other personal information?

While using cookies may be one method for gathering information, the easiest way for attackers to get access to personal information is to ask for it. By representing a malicious site as a legitimate one, attackers may be able to convince you to give them your address, credit card information, or other personal data. 

How can you limit the amount of information collected about you?

• Be careful supplying personal information - Unless you trust a site, don't give your address, password, or credit card information. Look for indications that the site uses SSL to encrypt your information. Although some sites require you to supply your social security number (e.g., sites associated with financial transactions such as loans or credit cards), be especially wary of providing this information online.
• Limit cookies - If an attacker can access your computer, he or she may be able to find personal data stored in cookies. You may not realize the extent of the information stored on your computer until it is too late. However, you can limit the use of cookies.
• Browse safely - Be careful which websites you visit; if it seems suspicious, leave the site. Also make sure to take precautions by increasing your security settings, keeping your virus definitions up to date, and scanning your computer for spyware.