Com Sci

Which of the following is the best description of the process of decryption?

Decoding data to reveal the original message

Which of the following situations is made possible thanks to public key encryption?

A customer enters their credit card number on a website, and the server securely receives the number without the possibility of cybercriminals seeing the credit card number.

For a long time, mathematicians weren't sure that asymmetric encryption was possible. Fortunately, cryptographers discovered the necessary mathematical innovation in the 1970s and invented public key encryption. If public key encryption was never invented, what wouldn't be possible today?

A customer logging into their bank website, with their password and secure code, without the risk of cybercriminals stealing their login information.

To celebrate National Teacher Day, a social media user starts a #MyFavTeacher hashtag and encourages other users to say thank you to their favorite teacher. The FBI is concerned about the trend and whether users will accidentally reveal information that can be used to answer bank account security questions. Which tweet would be the least concerning to the FBI?

"A big thanks to my third grade teacher! They got me started down the path of science experiments. #MyFavTeacher"

Amos decides to use a password manager to store their passwords and is currently coming up with a master password. Which of these is the strongest master password?

"aiwwdts1d&dd,Icub&m2md", an initialism based on song lyrics ("As I was walking down the street one dark and dreary day, I came upon a billboard and much to my dismay..")

Which of these combinations of evidence would count as two-factor authentication?

A number generated by a user's mobile application The name of the user's first grade teacher

In April 2020, Twitter users started a trend of posting their high school graduation photos. The FBI issued a warning soon after about the risks of posting those photos on public social media accounts. Which of these is not a potential risk of posting an old graduation photo?

An attacker could download the image and threaten to share it with the press unless the user gives them money.

Aisha sends an email message to her classmate Jamarion asking him to the prom. Which of these actions can Jamarion do without the consent of Aisha? 👁️Note that there may be multiple answers to this question. Choose all answers that apply:

Forward the message to another classmate Take a screenshot of the message Replying to the message with another classmate BCC'ed Reply to the message with another classmate CC'ed

What is a benefit of online collaborative software?

It allows for groups to work together even if they are not in the same geographic location.

In what way is multi-factor authentication (MFA) more secure than a password?

MFA adds an additional level of security for an attacker to break through.

A popular vlogger is worried about their video streaming account being broken into by attackers. The video streaming site offers them two options for authentication: a password or multi-factor authentication (with a password and SMS code). Which of these pieces of advice is accurate?

MFA will offer more security than a password, but they still need to be vigilant to protect their account from attackers.

Which of these users has the strongest password?

Marjorie combines 5 random words and alternates the casing: "scarves-TOKYO-theme-TEAMWORK-trulia".

Zaniyah wants to share photos of her newborn baby on her public social media account. She wants to be able to delete the posts once her baby grows up, however. How can she ensure she can completely delete the photos off the Internet later?

None of the above

In symmetric encryption, how many keys are needed to encrypt the data between a sender to a receiver?

One key: the same key is used for encryption and decryption, and that key is shared between the sender and receiver

Eloise wants to share her political views with family members living in another state but doesn't want her posts to be viewed by potential employers in the future. What is the best strategy for ensuring that?

She can send email messages with family members CC'ed on the email thread.

The Griffin family lives in multiple states, so they decide to use an online collaborative website to create their annual photo book. The website lets each of them upload photos from their computer, and then they can all arrange the photos into pages. What valid privacy concerns might the family members have? 👁️Note that there are 2 answers to this question.

The company that created the website now has a copy of the family's personal photos on their web servers. One of the family members could accidentally upload a photo that others did not want to be shared.

An account is protected by multi-factor authentication with these two factors: An alphanumeric password A code generated by a hardware device What would attackers have to steal to break in?

The password and the hardware device

Kira sends an email message to a teammate about a conflict she's having with their boss. They later discover that the boss found out about the contents of the message. What's the most likely way that happened?

The teammate forwarded the message to the boss.

When a computer wants to use public key cryptography to send data securely to another computer, those computers need to start a multi-step exchange of information. What is the first information exchanged?

The two computers send their public keys to each other.

A team of songwriters is working on song lyrics together for a pop star. They're trying to decide between two ways of working: Working on documents in a desktop text editing application and emailing their latest version of the document after editing them. Using an online collaborative text editor with real-time updates and revision history. Which of these is a benefit of using the online collaborative text editor?

With the online collaborative text editor, they can iterate more quickly on the lyrics and even edit at the same time.

Yuto posts a tweet on his Twitter account with a photo of himself taking a bubble bath. A few months later, while preparing for a job interview, he decides to delete the photo in case the job recruiters find it. Once Yuto deletes the tweet, can the recruiters find the photo?

Yes, if the tweet was archived by a web archive service or uploaded elsewhere by others who saw it.

A website is setting up a multi-factor authentication system and considering which evidence to ask for. They've narrowed the list down to these four: \text{I}Istart text, I, end text. The user's voice saying "Hello" \text{II}IIstart text, I, I, end text. The user's favorite song \text{III}IIIstart text, I, I, I, end text. A code sent to the user's cell phone \text{IV}IVstart text, I, V, end text. A password set by the user Which combinations of those would not count as a multi-factor authentication system?

\text{II}IIstart text, I, I, end text & \text{IV}IVstart text, I, V, end text (the song and password)

Public key encryption was invented in the 1970s, and since its discovery, it's enabled a wide range of secure transactions on the Internet. Which of these is not dependent on public key encryption for its security?

A teenager looks up information on a medical website in incognito mode, and won't have to see advertisements related to that medical condition in the future.

Which of the following best describes symmetric encryption?

An encryption scheme where the sender and receiver use the same shared key for encrypting and decrypting data.

Computer A is sending data securely to Computer B using public key encryption. In order for Computer A to encrypt the data, they need to use information from Computer B in a mathematical operation. What information from Computer B is used in that operation?

Computer B's public key

Which of these describes a multi-factor authentication system?

An enterprise website asks the user to enter a code generated by an application on their mobile phone. They then ask the user for their password.

Multi-factor authentication (MFA) is typically used in computing systems. However, we could imagine how MFA could be used in non-digital settings. If we were to protect the door to a castle with MFA, which of these would be considered multi-factor?

An outer door which requires a key and an inner door that requires a pin code.

Computer A wants to send data securely to Computer B using public key encryption. What information do they need from Computer B before Computer A can send the data?

Computer B's public key

A team is designing a new user interface for a website and deciding between two formats for collaboration: An in-person brainstorming session using paper, markers, and post-its A digital document in a productivity software suite that allows for simultaneous editing and comment threads What would be the benefit of collaborating with the digital document?

It would accommodate team members that could not attend the session in person.

How can attackers access a user account protected by two-factor authentication (2FA)?

It's possible for an attacker to break into an account secured with two-factor authentication, but only if they have access to both factors.

Rin doesn't want her parents to read her letters to her sister, so she uses a Vigenère cipher to make the letters secret. Her process: Rin shares the key ("BANANA") with her sister. Using the key, Rin turns the message "Ice cream time" into "Jcr ceebm gize". Rin sends a letter with "Jcr ceebm gize" to her sister. Using the key, her sister turns the message "Jcr ceebm gize" back into "Ice cream time". Which of these lists show an appropriate label for each step?

Key-sharing Encryption Communication Decryption

Lavanya is a startup founder who is working on the design of a smart bracelet. She needs to sketch out some ideas with a designer who lives in another country and wants to try using an online collaborative whiteboarding program for their design session. Lavanya is nervous about their design ideas being lost or getting into the wrong hands, however. Which of these is not a way that the whiteboarding data could be lost or stolen?

Lavanya could accidentally drop her laptop, resulting in a damaged hard drive and erased data.

Which statements are true about multi-factor authentication? 👁️Note that there are 2 answers to this question.

MFA adds an additional level of security to the authentication process. MFA requires evidence from at least two authentication factors.

Max decides to work with a tax accountant on putting together his taxes, since he finds it overwhelming to do all the paperwork himself. The accountant suggests using an online collaborative spreadsheet program to collect all the information necessary. Max is concerned that his tax information may get lost or stolen, however. Which of these is not a way that the tax information in the spreadsheet may get lost or stolen?

Max's partner could borrow his laptop and accidentally delete the tax information from the hard drive.

Benjamin is writing code for a medical software company. He would like feedback on his code and is considering either asking a colleague for an in-person code review or uploading the code to a collaborative code review program. What would be the most likely advantage of using collaborative code review software?

Multiple colleagues could see his code and give feedback on ways to improve it.

Each of these users has a different strategy to manage their passwords across websites. Which user's strategy is the strongest?

Pablo uses a password manager to generate strong passwords for each site. Their master password is an initialism, "iw2bacsMjrw1g2c!", based on their life goal ("I want to be a CS major when I go to college").

Leanne decides to use the Caesar Cipher encryption scheme to send a secret message to her classmate. Her process: Leanne shares the key (the number 13) with her classmate. Using the key, Leanne turns the message "Underground" into "Haqretebhaq". Leanne sends a letter with "Haqretebhaq" to her classmate. Using the key, her classmate turns the message "Haqretebhaq" back into "Underground". Which of the steps could be labeled the "decryption" step?

Step 4

A novelist is writing a new book. Her new editor asks her to use an online collaborative document editor to draft the book. She has some privacy concerns, however. Which of her privacy concerns are the most valid? 👁️Note that there are 2 answers to this question.

The editor can see how much time she spends writing in the document. The editor can see her typos and earlier drafts of the document.

The privacy policy for Twitter starts with this paragraph: Twitter is public and Tweets are immediately viewable and searchable by anyone around the world. We give you non-public ways to communicate on Twitter too, through protected Tweets and Direct Messages. You can also use Twitter under a pseudonym if you prefer not to use your name. This is a screenshot of the privacy settings for a particular user: Based on the policy and that setting, what is true about the user's tweets?

Their tweets are not publicly viewable.