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AP Comp Sci P



Big Idea 5: Impact of Computing

Safe Computing

7 min read•november 16, 2020


Minna Chow

AP Computer Science Principles ⌨️

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5.6 Safe Computing

Modern computing raises legal and ethical questions, one of which is a concern about security.
A key tenet of safe computing is protecting your personally identifiable information, or (PII). This is information that can be used to identify you and includes your:
  • Age
  • Race
  • Phone Numbers
  • Medical information and biometric data (fingerprints, eye scans)
  • Financial Information
  • Social Security number
Various other pieces of personal data, such as your location, cookies, and browsing history, can also be used to find your personal information.

Other Ways of Getting Info

  • Search engines can track your search history and use it to suggest websites and search phrases. They can also show you ads based on your search history, part of a process known as targeted marketing.
  • Devices, websites, and networks can collect information about a user's location, such as recording the IP address of the devices they use.

Benefits and Harms of PI Collection

The collection of personal information can be used to enhance your experience online. It can help you connect with friends on social media or find products best suited to you faster.
On the other hand, people are generally concerned about the rise of PI collection, and with good reason. Without strong protections, this collection of information might be exploited for ill.
For example, some personal information about your location and travel routes might be used for stalking purposes. Other pieces of personal information, especially your social security number, can be used to steal your identity. Companies that collect personal information could put their users at risk if they're hit by a data breach.
Another type of information on the internet that might harm you is the information you put online yourself. There's potentially a lot of information you can find out about someone just by looking at their social media accounts, from their appearance to where they work or go to school.
Social media posts can also harm you if the wrong message gets into the wrong hands. A nasty message or unwise photo may cause trouble for you if employers or college admissions officers get a hold of them, and it can be very difficult to delete information once it's out there.
It's a good idea, in general, to think carefully before you put anything on the internet. When in doubt, defer to the side of caution.

Other Dangers of Computing

  • Your computer might become infected with a virus or a worm. A virus is a malicious program. It's called a virus because, like a real virus, it can gain unauthorized access to something and then copy itself. Viruses are attached to infected files and must be activated by the user while worms can operate independently.
In 2000, the ILOVEYOU virus, named for the fake love-letter email it attached itself to, caused over ten billion dollars of damage across the world. In 2017, the WannaCry worm attack caused a similar amount of damage by encrypting hard drive files and holding them for ransom.
  • Computer viruses are a type of malware. Malware, short for malicious software, is intended to damage or take partial control over a computing system. It also includes ransomware and adware.
  • Scammers online can take advantage of human error to gain potentially harmful information. Phishing, for example, works by tricking users into providing their personal information by posing as a trustworthy group. For example, you might get a fake email from someone pretending to be your bank that says your credit card or bank account has an issue and they need your username and password to fix it. This information can then be used for a variety of misdeeds.
  • Scammers can also take advantage of keylogging technology, recording your keystrokes to gain access to sensitive information like passwords.
  • The information you send over public networks, like the Wifi network at a coffee store, has the potential to be intercepted by those with harmful ends. One of the ways this can happen is through a rogue access point, which gives unauthorized access to a secure network.
A key way to practice safe computing is to be wary. You never want to open or click any links in an email that you don't recognize the sender of. (Hackers can also gain access to people's accounts, so also be wary if you get a strange message from a friend.) Furthermore, be careful about what you download onto your devices; only download from websites you trust.
Fortunately, these concerns haven't gone unnoticed, and today there are many systems in place to help protect you on the internet.


Authentication measures keep people from gaining unauthorized access to your accounts. We're going to look at two of them here: making a strong password and implementing a multi-factor authentication method.
A strong password is a password that's easy for you to remember but difficult for someone else to guess, regardless of how well they know you. You don't want to use a generic phrase to create your password ("password," "12345,") or something that could be easily guessed at (your name, the name of your family members, etc.) Strong passwords often use a variety of characters, such as uppercase letters, numbers, and symbols (M4r13_cur13).
This website can help you determine how strong your password is, and also highlights what makes a password weak or strong.
You're mostly in charge of creating your own strong passwords, although many companies have implemented requirements for passwords to make them stronger. (They may require you to have a capital letter in your password, for example, or a symbol).
On the other hand, multifactor authentication is provided by the website you're using, although you can generally choose to opt in or out of it. Multifactor authentication is a way to control who gets access to your accounts by requiring multiple (at least two) methods of verification.
Typically, these proofs will fall into one of three categories, and they'll usually be in two separate categories.
  • Knowledge: this is something you know, like a password or PIN number. This can also include verification questions. (What's your favorite food? Where were you born?)
  • Possession: this is something that you have or own, such as a USB drive or an access badge. This can also include one-time passwords sent to a different device like your cell-phone.
  • Inheritance: this is something that you own intrinsically, like your fingerprints or voice.
A multifactor authentication system can provide multiple verification options for user convenience, as well as security. For example, a multifactor login method used for your email account might let you choose between sending a verification code to another email or to your phone in order to get in. That way, if you don't have your phone on-hand, you can still get into your account.
The more layers of verification you have, the more secure your account generally is, although there are limits and exceptions to the rule.


Encryption, another way of protecting people's data, is the process of encoding data to prevent unwanted access. (Decryption is the process of decoding data.) Traditionally, encryption was used to send and receive secret messages between spies or military generals. Coding mechanisms like the Caesar Cipher and the French Great Cipher became famous.
Both of these encryption methods use a key, or a secret piece of information, to keep their messages secret. Only the person the message is intended for should know the key.
For example, the Caesar Cipher works by shifting all the letters in a message down or up a given alphabet. In this case, the key is the number of letters that the message is shifted by. In the image below, all the letters are shifted up by 3: E becomes B, D becomes A, and so on. Therefore, the key is 3.

Image source: Matt_Crypto on Wikipedia

Today, you can use the computer to decode such simple codes quickly, and therefore more complex methods of encryption are needed.
Two common approaches to encryption are:
  • Symmetric key encryption, which uses one key for both encrypting and decrypting code.
  • Public key encryption, which uses a public key to encrypt but a private key to decrypt the message.
🔗 Check out this encryption overview, courtesy of Code.org!
The public key encryption system relies on digital certificates. These are issued by Certificate Authorities (CAs) to trusted sites. They allow other computers to verify that a website is who they say they are. These certificates are essential to the public key encryption system because they foster trust between websites. Think of the certificates to be a little like the signature on a check—once we see that signature, we know that the check is trustworthy.
A trust model is used in order to determine if a digital certificate itself is legitimate. (You won't have to understand how these models work for the AP test.)

Other Ways to Foster Safe Computing

  • Regular software updates help to patch up any errors or vulnerabilities that were previously undetected in the code.
  • Computer virus and malware scanning software can help protect your computer. Some famous brands are Norton and McAfee.
  • Firewalls, which monitor internet traffic and block websites deemed unsafe, can also help you protect your devices.
  • Making backups of important data can help mitigate the effects of your hardware failing or a virus attacking.
  • Knowing and controlling the permissions companies have to collect your data can empower you to decide what you're comfortable with.
  • Keeping your devices out of unsafe locations helps prevent them from being physically stolen or hacked into.
  • Being aware of internet connection security is also important. Free WiFi connections are often vulnerable to hackers.
  • Finally, stay informed! Technology is ever changing, and staying aware of these changes will help you protect yourself.


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