- A
Sign with private key, verify with public key
Correct process.
- B
Sign with public key, verify with private key
Why wrong: That would not provide non-repudiation.
- C
Sign with symmetric key, verify with asymmetric key
Why wrong: Digital signatures use asymmetric keys.
- D
Sign with hash, verify with private key
Why wrong: The hash is signed, but verification uses the public key.
Question 264 of 1,000
Digital Signatures: Using Private Key to Sign and Public Key to Verify
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.
A security engineer is implementing a digital signature scheme to ensure non-repudiation. Which process correctly describes how a digital signature is created and verified?
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
✓
Sign with private key, verify with public key
A digital signature is created by hashing the message and then encrypting that hash with the signer's private key. Verification is performed by decrypting the signature with the signer's public key and comparing the result to a freshly computed hash of the message. This asymmetric process ensures non-repudiation because only the private key holder could have created the signature, while anyone with the public key can verify it.
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.
- ✓
Sign with private key, verify with public key
Why this is correct
Correct process.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Sign with public key, verify with private key
Why it's wrong here
That would not provide non-repudiation.
- ✗
Sign with symmetric key, verify with asymmetric key
Why it's wrong here
Digital signatures use asymmetric keys.
- ✗
Sign with hash, verify with private key
Why it's wrong here
The hash is signed, but verification uses the public key.
Common exam traps
Common exam trap: answer the scenario, not the keyword
ISC2 often tests the misconception that the public key is used for signing because it is 'publicly available,' but the trap is that signing requires the private key to ensure only the claimed signer could have produced the signature.
Detailed technical explanation
How to think about this question
In practice, digital signatures follow standards like PKCS#1 v2.2 (RSA) or ECDSA (FIPS 186-5). The signature algorithm first computes a cryptographic hash (e.g., SHA-256) of the message, then applies the private key to that hash using a padding scheme like PSS or a deterministic ECDSA nonce. Verification recomputes the hash, decrypts the signature with the public key, and compares the padded hash values—any mismatch indicates tampering or forgery.
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
Symmetric Encryption Algorithm Comparison
| Algorithm | Key Size | Block Size | Status | Notes |
|---|---|---|---|---|
| AES-128 | 128-bit | 128-bit | Current standard | NIST approved; WPA3, TLS |
| AES-256 | 256-bit | 128-bit | Current standard | Preferred for sensitive / govt data |
| 3DES | 112-bit effective | 64-bit | Deprecated (2023) | Replaced by AES |
| DES | 56-bit | 64-bit | Broken | Cracked in < 24 h; never deploy |
| ChaCha20 | 256-bit | Stream cipher | Current | TLS 1.3, WireGuard |
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.
- →
Cryptography — study guide chapter
Learn the concepts, then practise the questions
- →
Cryptography practice questions
Targeted practice on this topic area only
- →
All SSCP questions
1,000 questions across all exam domains
- →
Systems Security Certified Practitioner SSCP study guide
Full concept coverage aligned to exam objectives
- →
SSCP practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SSCP practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Access Controls practice questions
Practise SSCP questions linked to Access Controls.
Risk Identification, Monitoring, and Analysis practice questions
Practise SSCP questions linked to Risk Identification, Monitoring, and Analysis.
Incident Response and Recovery practice questions
Practise SSCP questions linked to Incident Response and Recovery.
Security Operations and Administration practice questions
Practise SSCP questions linked to Security Operations and Administration.
Cryptography practice questions
Practise SSCP questions linked to Cryptography.
Network and Communications Security practice questions
Practise SSCP questions linked to Network and Communications Security.
Systems and Application Security practice questions
Practise SSCP questions linked to Systems and Application Security.
Risk Identification, Monitoring and Analysis practice questions
Practise SSCP questions linked to Risk Identification, Monitoring and Analysis.
SSCP fundamentals practice questions
Practise SSCP questions linked to SSCP fundamentals.
SSCP scenario practice questions
Practise SSCP questions linked to SSCP scenario.
SSCP troubleshooting practice questions
Practise SSCP questions linked to SSCP troubleshooting.
Practice this exam
Start a free SSCP practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
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: Sign with private key, verify with public key — A digital signature is created by hashing the message and then encrypting that hash with the signer's private key. Verification is performed by decrypting the signature with the signer's public key and comparing the result to a freshly computed hash of the message. This asymmetric process ensures non-repudiation because only the private key holder could have created the signature, while anyone with the public key can verify it.
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.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
2 more ways this is tested on SSCP
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. An organization is implementing a digital signature solution to ensure non-repudiation of documents. Which combination of keys is used during the signing process?
medium- A.Recipient's public key to sign, recipient's private key to verify
- ✓ B.Sender's private key to sign, sender's public key to verify
- C.Sender's public key to sign, recipient's private key to verify
- D.A shared symmetric key for both signing and verification
Why B: Digital signatures use asymmetric cryptography where the sender creates a signature with their private key, and the recipient verifies it with the sender's public key. This ensures non-repudiation because only the sender possesses their private key, so they cannot deny having signed the document. The process typically involves hashing the document and encrypting the hash with the sender's private key.
Variation 2. An organization is implementing a digital signature solution to ensure non-repudiation and integrity of documents. Which three of the following are true regarding digital signatures?
medium- A.The receiver uses the sender's private key to verify the signature.
- ✓ B.The receiver verifies the signature using the sender's public key.
- C.The sender encrypts the entire document with their public key to create a signature.
- ✓ D.Digital signatures provide non-repudiation because the private key is kept secret by the sender.
- ✓ E.The sender signs the message hash with their private key.
Why B: Digital signatures involve signing the hash of the message with the sender's private key. They provide non-repudiation because only the sender has the private key. Verification uses the sender's public key.
Keep practising
More SSCP practice questions
- A company has implemented a new vulnerability scanner and the first scan reports 200 vulnerabilities. The security team…
- A security analyst is reviewing logs and notices multiple failed login attempts from a single IP address against an admi…
- A security manager is evaluating log sources for a SIEM implementation. Which THREE of the following are considered log…
- A vulnerability scanner reports a medium-severity finding on a server. After investigation, the security team determines…
- During a qualitative risk analysis, an organization rates the likelihood of a flood as 'Low' and the impact as 'High'. U…
- A security analyst is tuning a SIEM to reduce false positives. Which of the following actions is most likely to reduce f…
Last reviewed: Jul 4, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.