1.4 Explain the importance of using appropriate cryptographic solutions
Objective 1.4 sits in General Security Concepts, which carries 12% of the Security+ exam. The questions below are original, written from the official objective title above, and each explanation cites the CompTIA page it rests on.
Objective title verbatim from the official objectives. CompTIA exam page ↗
A worked example
Shown solved, with the whole explanation open: this is what every question here carries.
A team wants to use one symmetric key for both encrypting stored data and generating message authentication codes to reduce key management overhead. What risk does this design create?
The concept
Best practice limits each key to a single purpose because reuse across functions can undermine the security of one or both operations and expands the impact of a compromise.
Why this answer
Reusing a key for encryption and for MAC generation can weaken the guarantees of either or both operations, which is why single-purpose key usage is recommended.
- This is correct: dual-purpose use is a security weakness, not a mathematical impossibility.
- BSymmetric keys can technically be reused across algorithms; the concern is security weakening, not mathematical infeasibility.
- CMACs are typically generated with symmetric keys, not asymmetric key pairs.
- DElliptic curve algorithms are unrelated to the key-reuse problem described here.
Now you: objective 1.4 questions
No account needed. The explanation opens when you answer.
Sample question 1 of 2
A storage system uses a 128-bit block size key that has now encrypted roughly 295 exabytes of data, matching the documented threshold for that block size. What should the security team do?
Sample question 2 of 2
A developer generates password reset tokens using a language's default random() function instead of a cryptographic library call. What risk does this introduce?
That’s 2 of the full Security+ bank.
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Continue practicingRead the sources
These are the official pages the questions above cite. Reading them is studying the objective from the primary source, which is what the explanations point you toward anyway.