SY0-701 Question 33
Single answer1.4 Explain the importance of using appropriate cryptographic solutions.A healthcare company is deploying a new patient portal that allows patients to view lab results, message providers, and upload insurance documents. The security team must protect data in transit over the internet, ensure uploaded documents cannot be modified without detection, and minimize the risk of exposing private keys stored on the web servers. Which solution BEST meets these requirements?
- A
Use TLS with certificates on the web servers, have the application hash uploaded documents with SHA-256 to verify integrity, and store server private keys in a hardware security module (HSM)
- B
Use WPA3 for all patient portal traffic, encrypt uploaded documents with AES-128 in ECB mode, and store server private keys in a password-protected text file
- C
Use MD5 to verify uploaded documents, use self-signed certificates for public access, and export server private keys to each administrator's workstation for backup
- D
Use plaintext HTTP behind a reverse proxy, sign uploaded documents with DES, and store server private keys in the web server's source code repository
Show answer and explanation
Correct answer: A
Explanation
This scenario tests the ability to select appropriate cryptographic solutions for confidentiality, integrity, and key protection in a real-world web application. For public-facing portals, TLS is the standard control for protecting data in transit. For integrity, modern hash algorithms such as SHA-256 are appropriate, while older algorithms like MD5 are no longer recommended for security-sensitive use. For key management, private keys should be strongly protected, and HSMs are widely recognized as a best practice because they provide tamper resistance, restricted key access, and stronger lifecycle management. These choices align with common best practices reflected in NIST guidance, including NIST SP 800-52 for TLS, NIST SP 800-131A on transitioning away from weak algorithms such as MD5 and DES, and general NIST key-management guidance in SP 800-57.
- A. Correct.
Correct. TLS is the appropriate cryptographic solution for protecting web application traffic in transit across untrusted networks. Hashing uploaded documents with SHA-256 provides a practical way to detect unauthorized modification and supports integrity verification. Storing private keys in an HSM is a best practice because it provides strong protection for key material, often preventing keys from being directly exported and reducing exposure if a server is compromised.
- B. Incorrect.
Incorrect. WPA3 protects wireless network access, not end-to-end internet traffic to a public web application. AES is a strong cipher, but ECB mode is not appropriate for protecting document contents because it leaks patterns and is considered insecure for most data encryption use cases. Storing private keys in a password-protected text file is weak key management and does not adequately protect highly sensitive cryptographic material.
- C. Incorrect.
Incorrect. MD5 is deprecated for security-sensitive integrity validation because collision attacks make it unsuitable for trustworthy document verification. Self-signed certificates are generally not appropriate for a public-facing patient portal because users and browsers cannot inherently trust them like certificates issued by a trusted public CA. Exporting private keys to administrator workstations increases the attack surface and undermines secure key management.
- D. Incorrect.
Incorrect. Plaintext HTTP does not protect confidentiality or integrity of patient data in transit, even if a reverse proxy exists, unless TLS is properly implemented where the client connects. DES is obsolete due to its small key size and is not appropriate for modern security requirements. Storing private keys in source code repositories is a severe security failure because repositories are often broadly accessible and not designed for secure key custody.