Hash Algorithm for Data Integrity Verification

SY0-601 By islever Editorial Last updated

Short answer

A A Hash algorithm generates a unique digital fingerprint to verify that data has not been altered or tampered with.

Question

Which of the following is an algorithm performed to verify that data has not been modified?
  1. Hash Correct Answer
  2. Code check
  3. Encryption
  4. Checksum

Key Takeaways

The exam tests the nuance between error detection (checksum) and integrity verification (hash), with the common trap being the selection of checksum due to its simpler definition of 'checking' data.

This question tests the ability to distinguish between hash functions and checksums in the context of data integrity. It establishes that cryptographic hashing is the superior method for verifying that data has not been modified, especially against intentional tampering.

Common mistake: Candidates often select D (Checksum) because it is technically an algorithm used to detect errors, but they fail to recognize that Hash algorithms are designed specifically for robust integrity verification and security, making them the better answer for 'not modified'.

Expert Analysis

Why the Answer Is Correct

A hash algorithm is the correct choice because it produces a fixed-size digest that is highly sensitive to any change in input data. In cybersecurity contexts, particularly for certifications like CompTIA Security+, 'verifying data has not been modified' implies ensuring integrity against both accidental corruption and malicious tampering. Cryptographic hash functions (like SHA-256) are designed to be collision-resistant and pre-image resistant, providing a strong assurance that the data is authentic and unaltered.

Why the Other Options Are Wrong

Code check (B) is too vague and not a standard cryptographic term for integrity. Encryption (C) is used for confidentiality, not primarily for integrity verification; while some modes provide integrity, encryption alone does not verify modification without additional mechanisms like MACs or digital signatures. Checksum (D) is the most common distractor; while checksums detect accidental errors (like transmission noise), they are not cryptographically secure and can be easily manipulated by an attacker to maintain the same checksum after modifying the data.

Community Comment Notes

Many learners initially chose Checksum, arguing that it detects errors in transmission. However, comments highlighted that Hashes are 'better' and more 'robust' for integrity. One commenter noted that checksums are 'simpler and less secure,' intended only for error detection, whereas hashes are 'resistant to intentional tampering.' Another pointed out that the question asks for an 'algorithm' and while both are algorithms, the semantic weight of 'verify not modified' leans toward the cryptographic strength of hashing. The consensus among top-voted comments supports A as the definitive answer for integrity assurance.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

When asked about data integrity, look for keywords like 'tamper-proof', 'authenticity', or 'cryptographic'. If both Hash and Checksum are options, choose Hash unless the scenario specifically mentions simple error detection in non-security critical transmissions (e.g., basic network packet validation).

Frequently Asked Questions

Why is Checksum wrong if it also checks data?

Checkums detect accidental errors but lack cryptographic security. They cannot reliably verify that data was not intentionally modified by an attacker.

What is the difference between Hash and Encryption?

Encryption protects confidentiality by scrambling data with a key. Hashing creates a fixed digest to verify integrity; it is one-way and does not use a key for decryption.

More SY0-601 FAQ →

Community Votes

A
63%
D
37%

63% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 22 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 22

  1. 1403ad2 👍 16
    choose A 2024-20-2 On Test and passed with 802
  2. ganymede 👍 7 Answered A
    A. Hash Both hash and checksum can validate integrity. But hashing algorithms are better.
  3. slapster 👍 4 Answered A
    I think the semantics of the question are the key here. It is by no coincidence that both hash and checksum are answer choices. At first, I read the question and thought, wth both a checksum and hash value are used to establish integrity. Why am I even being asked to differentiate between the two?? Upon re-reading the question, it clicked that we are being asked to identify an ALGORITHM that establishes the integrity. A checksum is simply the output of an algorithm, therefore hash seems to be the best answer here.
  4. CaNe2o1 👍 4 Answered A
    Checksum: While checksums are used to detect errors in data transmission or storage, they are not as robust as hash functions for verifying data integrity. Checksums can detect errors, but they are not designed to verify that data has not been modified intentionally.
  5. Paula77 👍 4 Answered D
    A checksum is calculated from a block of digital data with the scope of being used in error detection. Its main function is to detect errors which may have been introduced during its transmission or storage.
Show 17 more comments
  1. [Removed] 👍 3 Answered D
    A checksum is the outcome of running an algorithm, called a cryptographic hash function, on a piece of data, usually a single file. Comparing the checksum that you generate from your version of the file, with the one provided by the source of the file, helps ensure that your copy of the file is genuine and error free.
  2. Kartabk 👍 3 Answered A
    while both checksums and hash functions are used to verify data integrity, checksums are simpler and less secure, primarily intended for error detection. Hash functions are more complex, resistant to intentional tampering, and suitable for cryptographic applications where data security is crucial.
  3. agfencer 👍 2 Answered A
    A. Hash functions are designed to detect changes in data. If the data is modified, even slightly, the hash value will change significantly, indicating that the data has been altered. WHY NOT CHECKSUM> While checksums can detect changes, they are generally simpler and less secure compared to cryptographic hash functions. Checksums are used for error-checking but may not be as reliable as hashes for verifying data integrity due to their susceptibility to collisions and less robust algorithms.
  4. ID77 👍 2 Answered A
    Hashes are used to verify that data is not modified, tampered with, or corrupted. Hashes are more longer numbers and used in strong cryptographic implementations. Checksum is a small piece of data used to quickly verify the integrity of the data.
  5. _deleteme_ 👍 2
    Per Dion Study Guide 601 pg124, using a hash algorithm creates a level of assurance to the integrity and authenticity of given message or file.
  6. Payu1994 👍 1
    The algorithm performed to verify that data has not been modified is: A. Hash Explanation: Hash (Option A): A hash function takes input data and produces a fixed-size string of characters, which is typically a hexadecimal number. The hash value, or hash code, is unique to the input data. By comparing the hash value of the original data with the hash value calculated from the received or stored data, one can determine whether the data has been modified. If the hash values match, the data is likely unchanged; if they differ, it indicates that the data has been altered.
  7. BD69 👍 1 Answered A
    For starters, checksums can have collisions (lots of them). Because of this, checksums are the worst choice for verifying that data has not been modified and certainly offers no guarantee. Cryptographic hashes like MD5 or better are designed to be collision resistant.
  8. DrCo6991 👍 1 Answered D
    Checksum gets my vote. https://www.techtarget.com/searchsecurity/definition/cryptographic-checksum
  9. MortG7 👍 1
    A Checksum is the outcome of running an algorithm, called a cryptographic hash function.
  10. qwes333 👍 1 Answered D
    It's D. Checksum Checksum -> verify the integrity Hash -> protect against X
  11. chizzuck 👍 1 Answered A
    a Hash. A checksum is weaker than a hash and should not replace a hash
  12. russian 👍 1 Answered A
    you check the hash to verify that its the same as before
  13. ekiel 👍 1 Answered D
    D . Checksum verifies or checks the integrity of data
  14. johnabayot 👍 2 Answered D
    D. Checksum
  15. russian 👍 1 Answered A
    You compare hashes to verify
  16. NetworkTester1235 👍 1 Answered D
    Checksums provide integrity
  17. KC1008 👍 1 Answered D
    Checksum

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