Which of the following data protection strategies can be used to confirm file integrity?

Hashing is a cryptographic process that generates a unique, fixed-size string of characters, known as a hash value or digest, from a given input file or data. A core property of a secure hash function is that any change to the input data—even a single bit—will result in a drastically different hash value. By calculating the hash of a file and comparing it to a previously stored, trusted hash value for that same file, one can definitively verify whether the file has been altered or corrupted. This process directly confirms the file's integrity.

A. Masking: This technique protects data confidentiality by replacing sensitive information with fictitious but realistic-looking data, primarily for use in non-production environments. It does not verify integrity.

B. Encryption: The primary purpose of encryption is to ensure confidentiality by rendering data unreadable without the proper key. It does not, by itself, guarantee that the data has not been altered.

D. Obfuscation: This is the practice of making code or data difficult for humans to understand. It is a method to protect intellectual property or hide logic, not to check for data integrity.

1. National Institute of Standards and Technology (NIST). (2020). Guideline for Using Cryptographic Standards in the Federal Government: Cryptographic Mechanisms (NIST Special Publication 800-175B Revision 1).

Section 5.3

"Hash Functions

" states: "A primary use of hash functions is for the generation and verification of digital signatures... Another use is for the generation of a message authentication code (MAC)... Both of these uses provide data integrity."

2. Rivest

R. (2017). Lecture 5: Hash Functions. MIT OpenCourseWare

6.857 Computer and Network Security.

The lecture notes explicitly state that a key application of collision-resistant hash functions is for "Message integrity

" where one can "Compute h(M)

save h(M) securely. Later

can check if M is modified by recomputing h(M)."

3. Katz

J.

& Lindell

Y. (2020). Introduction to Modern Cryptography (3rd ed.). Chapman and Hall/CRC.

Chapter 5

Section 5.1

"Definitions

" describes how hash functions are used for verifying file integrity. The text explains that a server can post a hash of a file

and a user who downloads the file can compute the hash locally and compare it to the server's value to ensure the file was not modified during download.