Free Practice Quiz Question List

4 Cryptography Basics Online Quiz Questions

Use this free practice quiz with 20 questions to review 4 Cryptography Basics, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

A system needs to keep messages confidential and detect tampering. It should not assume that ordinary encryption alone provides both protections.

A
True
B
False

Choose one

1 point

A sender encrypts a message for Bob using a public-key encryption scheme. Which key should Bob use to decrypt it?

A
Bob’s public key
B
Bob’s private key
C
The sender’s private key
D
A certificate authority’s key

Fill in the blank

1 point

A digital certificate binds a website’s identity to its .

Written response

1 point

Which two properties should a password-hashing scheme have to avoid relying on a fast general-purpose hash alone? Enter both properties in the format “X and Y.”

Choose one

1 point

A team needs to encrypt a large file efficiently, and the sender and recipient already share a secret key. Which approach best fits this task?

A
Use a digital signature algorithm to encrypt every part of the file.
B
Use a symmetric algorithm such as AES to encrypt the file.
C
Use an unkeyed hash function to encrypt the file.
D
Use a certificate authority to encrypt the file.

True or false

1 point

A digital signature can help verify data and its origin, but signing the data does not by itself make the data confidential.

A
True
B
False

Fill in the blank

1 point

To authenticate data and check its integrity using a shared secret, a system can use a keyed .

Written response

1 point

A cryptographic hash function maps data to a fixed-length value. What is that output called?

Choose all

1 point

Which statements about digital signature verification are supported? Select all correct answers.

A
Verification can provide evidence that the signed data has not changed.
B
Verification can provide evidence that the signature was made with the private key corresponding to the public key used for checking.
C
A valid signature by itself proves the signer’s real-world identity.
D
A digital signature encrypts the signed data.

Choose one

1 point

Two parties share a secret and need to check that a message has not changed and was created by someone with that secret. Which tool best fits their need?

A
An unkeyed hash, because anyone can calculate it.
B
A digital certificate, because it encrypts the message.
C
A keyed message authentication code (MAC), because the parties share a secret.
D
A plaintext checksum, because it identifies the sender.

Choose all

1 point

When a browser evaluates a website’s certificate, which checks are appropriate? Select all correct answers.

A
Check whether the certificate is valid for the requested domain name.
B
Check whether its path chains to a trusted certificate authority.
C
Check details such as its validity period and intended use.
D
Assume the certificate encrypts the traffic without further steps.
E
Accept any public key presented by the website without validation.

Open ended

1 point

A team is designing a browser-to-server connection that must authenticate the server and protect a large amount of data. Describe a suitable approach using certificate validation, the TLS handshake, and encryption. Include one key-management precaution.

Choose one

1 point

A service stores a message alongside its unkeyed hash. If an attacker can change both the message and the stored hash, what conclusion is correct?

A
The hash alone proves who created the message because it has fixed length.
B
The hash alone does not prove who created the message, because an attacker could calculate a new hash after changing it.
C
The hash encrypts the message so only its creator can read it.
D
The hash proves the message came from a trusted certificate authority.

Choose one

1 point

A team encrypts a file with a secret key shared by its sender and recipient. The recipient uses that same key to recover the file. Which kind of cryptography describes this arrangement?

A
Asymmetric cryptography, because each party uses a different key
B
Symmetric cryptography, because the same secret key is used for both operations
C
Hashing, because both parties calculate a digest
D
Digital signatures, because the sender creates a signature

Choose one

1 point

Two organizations need to establish shared key material, but they have not first distributed a shared secret key. Which approach is supported by the material?

A
Send a shared secret in an ordinary message before using cryptography
B
Use a hash function to turn the message into a shared secret
C
Use an asymmetric method to help establish shared key material
D
Use a digital certificate as the secret key

Choose one

1 point

A development team is choosing how to implement cryptographic protection for a new product. Which plan best follows the practical principles?

A
Adopt established protocols and reputable, maintained software
B
Design a new encryption algorithm so the organization controls every detail
C
Use an unverified public key if it makes deployment faster
D
Store keys with unrestricted access so recovery is simpler

Choose one

1 point

A system requirement is to establish which service is communicating with a client. Which cryptographic goal most directly matches that requirement?

A
Confidentiality
B
Integrity
C
Key rotation
D
Authentication

True or false

1 point

In asymmetric cryptography, the public key can be shared, while the corresponding private key must be protected.

A
True
B
False

Written response

1 point

Public-key methods can help parties set up shared key material without first distributing a shared secret. What is this task called?

Written response

1 point

A system needs to establish who or what is communicating. What cryptographic goal does this describe?