Password storage and hashing

ID: 5.7.3 Level: 3 Parent: Password policies and multi-factor authentication enforcement Tags: #level3 #cryptography #module5

Overview

This topic addresses a specific domain of knowledge within the broader security landscape, providing detailed exploration of concepts, techniques, and best practices. Understanding this material is essential for implementing effective security controls and conducting thorough security assessments.

The content presented here synthesizes industry standards, research findings, and practical experience to offer actionable guidance. Learners will gain insights into both defensive and offensive security perspectives, enabling comprehensive security analysis and decision-making.

Key Concepts

Data integrity ensures that information remains accurate, complete, and unmodified except through authorized processes. Hash functions generate fixed-size outputs from variable inputs, creating unique ‘fingerprints’ that can detect any alteration to the original data. Cryptographic hash functions must be collision-resistant, meaning it should be computationally infeasible to find two inputs producing the same output.

Digital signatures combine hashing and asymmetric encryption to provide both integrity verification and non-repudiation. When a document is digitally signed, the sender’s private key encrypts a hash of the content. Recipients can verify authenticity using the sender’s public key, confirming both the sender’s identity and that the content hasn’t been altered.

Modern applications implement integrity controls through various mechanisms including checksums, message authentication codes (MACs), and blockchain technologies. Version control systems maintain audit trails of all changes, enabling detection of unauthorized modifications and providing the ability to restore previous states.

Practical Applications

Security professionals apply these concepts across diverse organizational contexts, adapting principles to specific technical environments, business requirements, and risk profiles. Implementation requires balancing security effectiveness with operational feasibility, user experience, and resource constraints.

Successful implementations involve collaboration across technical teams, business units, and management. Security cannot be imposed unilaterally but must integrate with existing processes and workflows. Pilot programs test new controls on limited scope before organization-wide deployment, allowing refinement based on practical experience.

Security Implications

Compromised credentials enable attackers to masquerade as legitimate users, bypassing technical security controls. Credential stuffing attacks leverage passwords leaked from other breaches, succeeding when users reuse passwords across services. Multi-factor authentication significantly reduces credential compromise risk, though phishing-resistant methods like FIDO2 hardware tokens provide stronger protection than SMS or app-based codes.

Insider threats, whether malicious or negligent, exploit legitimate access for unauthorized purposes. Least privilege access controls limit damage from compromised accounts. User and Entity Behavior Analytics (UEBA) detect anomalous activities indicating compromised accounts or malicious insiders, such as accessing unusual resources or exfiltrating large data volumes.

Tools & Techniques

John the Ripper: Password cracking tool supporting numerous hash formats. Wordlist, brute force, and hybrid attack modes enable recovery of weak passwords. Hashcat: High-performance password recovery tool leveraging GPUs for acceleration. Supports hundreds of hash algorithms with optimized kernels for each. Mimikatz: Post-exploitation tool for extracting credentials from Windows systems. Retrieves plaintext passwords, hashes, and Kerberos tickets from memory.

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References & Further Reading

  • NIST National Vulnerability Database: https://nvd.nist.gov/
  • SANS Reading Room: https://www.sans.org/reading-room/
  • Common Vulnerabilities and Exposures (CVE): https://cve.mitre.org/
  • Industry white papers and research publications
  • Vendor security documentation and best practice guides
  • Security blogs and conference presentations

Note: This is part of a comprehensive Zettelkasten knowledge base for cybersecurity education. Links connect to related concepts for deeper exploration.