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Cryptography Concepts Quiz

Test your knowledge on cryptography and its various concepts with our comprehensive quiz! This engaging set of questions covers topics ranging from group theory to advanced hash functions and encryption methods.

Challenge yourself and improve your understanding of:

Groups and rings in mathematics
Hash functions and security models
Encryption techniques like AES and Feistel networks
Message Authentication Codes (MACs)

13 Questions3 MinutesCreated by EngagingCoder317

Choose the incorrect option(s) from the following:

(R,× ) is a group

(R-{0},+) is a group

(ℤ – {0}, +) is an abelian group

(R -{0} ,× ) is a group

Select the incorrect option(s) for the Merkle-Damgård transformation:

It employs a multi-stage approach and used in many popular hash algorithms like MD5, SHA256

This construction will always add a padding to the message which depends upon the length of the message

The initial vector (IV) used in this construction can be randomized

The transformation is a deterministic function of the input

Given H is a collision-resistant hash function. Then which of the following is/are false?

The function H_1 (x)≝H(x)||H(x) is not collision-resistant

The function H_1 (x)≝H(x)||H(x) is collision-resistant

The function H_2 (x)≝1||H(x) is collision-resistant

The function H_2 (x)≝1||H(x) is not collision-resistant

Neither the construction in part (a), nor the construction in part(b) is secure

The construction in part (a), as well as the construction in part(b) are secure

Choose the option(s) that is/are correct for AES

AES block cipher has a 128-bit block length and uses an 128-bit key

AES is a substitution-permutation network

AddRoundKey, SubBytes, ShiftRows, MixColumns are the four operations that are applied in a series of four stages

AES block cipher is proven to be secure against computationally bounded adversary

Which of the following is(are) incorrect?

In a CCA attack, the adversary can ask for decryptions of any ciphertext of its choice

The CCA-security model captures a malicious adversary

The CCA-security model captures a passive adversary

Providing decryption-oracle to the adversary does not provide any additional power to the adversary

Which of the following is/are false about Message Authentication Codes?

CBC MAC can be used to generate tag for only fixed-length messages

Block-wise CBC MAC initialized with IV=0^n, instead of IV being the number of message blocks is insecure

A secure MAC maintains the privacy of the underlying message

A secure MAC has to be always randomized

Given encryption scheme is single-message CCA secure.

Given encryption scheme is single-message CPA secure.

Given encryption scheme is neither CCA-secure, nor CPA-secure.

The construction is CMA-secure

The construction is SCMA-secure

The tag-generation algorithm is deterministic

The tag-generation algorithm is randomized

Which of the following is/are false about modes of operation?

A sequence of n messages can be encrypted using block cipher by making less than n calls to a secure PRF

Cipher-text computation is parallelizable in CTR mode.

Plain text of any length can be encrypted in OFB mode

Stateful variant of Counter mode is secure where as that of OFB mode is insecure

Which of the following is(are) true about Feistel and SPN networks?

SPRP can be constructed using 4-round Feistel network

Diffusion is used to produce avalanche effect in an SPN

S-boxes are used to produce confusion in an SPN

All of these

Consider the stateless variant of CBC-mode of encryption with a block cipher having a 256-bit key and 128-bit block length to encrypt a 512-bit message. The length of the resulting ciphertext in bits is:

256

640

128

None

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Cryptography Concepts Quiz

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