Question 403 of 1,000
CryptographyeasyMultiple ChoiceObjective-mapped

SSCP Cryptography Practice Question

This SSCP practice question tests your understanding of cryptography. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

What is the minimum recommended RSA key size for secure use as of current best practices?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "best"

    Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

  • Clue: "minimum / minimize"

    Why it matters: Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

2048 bits

Option D (2048 bits) is correct because current best practices, as recommended by NIST SP 800-57 and other cryptographic standards, consider 2048-bit RSA keys as the minimum secure size for protecting data through 2030. This key length provides a sufficient security margin against known factoring attacks, balancing computational efficiency with cryptographic strength.

Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • 1024 bits

    Why it's wrong here

    1024-bit is considered weak.

  • 4096 bits

    Why it's wrong here

    4096 is stronger but not the minimum.

  • 3072 bits

    Why it's wrong here

    3072 is also acceptable but not the minimum.

  • 2048 bits

    Why this is correct

    2048-bit is the minimum recommended.

    Clue confirmation

    The clue words "best", "minimum / minimize" in the question point toward this answer.

    Related concept

    Read the scenario before looking for a memorised answer.

Common exam traps

Common exam trap: answer the scenario, not the keyword

Cisco often tests the misconception that larger keys are always better, leading candidates to choose 4096 bits as the minimum, when in fact 2048 bits is the officially recommended baseline for secure use.

Detailed technical explanation

How to think about this question

RSA security relies on the difficulty of factoring the product of two large primes; a 2048-bit modulus corresponds to approximately 112 bits of symmetric key security, matching the strength of AES-128 for most practical purposes. The transition from 1024 to 2048 bits was driven by the successful factorization of 768-bit RSA in 2009 and the projected feasibility of factoring 1024-bit keys within a decade using improved algorithms like the Number Field Sieve. In real-world scenarios, using keys larger than 2048 bits can cause performance issues in TLS handshakes and smart card operations, where computational overhead is critical.

KKey Concepts to Remember

  • Read the scenario before looking for a memorised answer.
  • Find the constraint that changes the correct option.
  • Eliminate answers that are true in general but not in this case.

TExam Day Tips

  • Watch for words such as best, first, most likely and least administrative effort.
  • Review why wrong options are wrong, not only why the correct option is correct.

Key takeaway

Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.

Real-world example

How this comes up in practice

A developer is choosing between AES-256 (symmetric) and RSA-2048 (asymmetric) for encrypting a large file that will be sent to a partner. Symmetric encryption is fast but requires key exchange; asymmetric is slower but solves the key distribution problem. A hybrid approach — encrypt the file with AES, encrypt the AES key with RSA — is standard. Questions like this test whether you understand when each approach applies.

Quick reference

Asymmetric Encryption Algorithm Comparison

AlgorithmKey ExchangeSignaturesEquivalent Security KeyNotes
RSA-3072YesYes128-bitWidely deployed; slow for bulk data
ECDSA P-256NoYes128-bitFast signatures; standard TLS certs
ECDH / ECDHEYesNo128-bitPerfect forward secrecy in TLS 1.3
DH / DHEYesNo128-bit (3072-bit key)Replaced by ECDHE in modern TLS
Ed25519NoYes~128-bitSSH keys, modern PKI

What to study next

Got this wrong? Here's your next step.

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

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FAQ

Questions learners often ask

What does this SSCP question test?

Cryptography — This question tests Cryptography — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: 2048 bits — Option D (2048 bits) is correct because current best practices, as recommended by NIST SP 800-57 and other cryptographic standards, consider 2048-bit RSA keys as the minimum secure size for protecting data through 2030. This key length provides a sufficient security margin against known factoring attacks, balancing computational efficiency with cryptographic strength.

What should I do if I get this SSCP question wrong?

Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.

Are there clue words in this question I should notice?

Yes — watch for: "best", "minimum / minimize". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jul 4, 2026

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This SSCP practice question is part of Courseiva's free ISC2 certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SSCP exam.