What is application security?

Application security is the tools, processes, and best practices used to protect software applications from cyber threats throughout their entire lifecycle, from design and development to deployment and ongoing use. It ensures that your software is safe from hackers, data leaks, and misuse, focusing on preventing vulnerabilities (weak points attackers can exploit) and mitigating risks that could lead to breaches, downtime, or compromised data.

Why application security matters

According to AWS, application security benefits organizations by ensuring:

• “Enhances user trust: Security incidents from within your applications can affect user trust in your business and have an impact on brand reputation. Focusing on application security helps prevent against this possibility and can enhance user loyalty.
• Supports regulatory compliance: Organizations producing software applications that meet compliance frameworks must work hard to ensure these products remain compliant. For example, if an application meets the General Data Protection Regulation (GDPR), all new features must also be GDPR compliant.
• Maintains business operations: An active threat within an organization can bring operations to a halt. Ensuring your software application is not the cause of a security incident will help keep business operations running as smoothly as possible.
• Safeguards sensitive data: Sensitive data, such as personally identifying information (PII) and private business information flow through applications. By prioritizing application security, you can implement security practices to help prevent unauthorized access and protect against data breaches.”
  
  

Types of application security

According to IBM, there are five types of application security, namely authentication, authorization, encryption, logging, and testing. Each type plays a unique role in strengthening the security posture of an application across its lifecycle.

Authentication

Authentication verifies that a user is who they claim to be before granting access to an application. This is the first line of defense against unauthorized access.

Modern applications use several forms of authentication, including:

• Passwords
• Biometrics (fingerprint or facial recognition)
• Physical or hardware tokens
• Multifactor authentication (MFA), which combines two or more of the above factors

By implementing strong authentication mechanisms, developers ensure that only legitimate users can enter the system.

Read more: What is user authentication?

Authorization

Once a user has been authenticated, authorization determines what they are allowed to do. It focuses on access control, defining which resources, data, or functionalities a user can access within the application.

This process usually relies on:

• Identity and Access Management (IAM) systems
• Role-based access control (RBAC)
• Attribute-based access control (ABAC)

Authorization compares the user’s identity and privileges against a predefined list of permitted actions, ensuring that sensitive features or data remain accessible only to appropriate users.

Read also: FAQs: HIPAA authorizations

Encryption

Encryption protects sensitive information by converting it into unreadable code, ensuring confidentiality even if data is intercepted or accessed without permission. It is crucial to protect data both in transit (while moving across networks) and at rest (stored on servers or devices).

Logging

Logging provides visibility into how an application is being used and is essential for detecting and investigating security incidents. Application logs capture:

• User activities
• Access patterns
• System errors
• Suspicious or unauthorized actions

Logs typically include timestamps, user IDs, and details about the specific actions performed. During or after a breach, logs are invaluable for tracing the attacker’s actions, identifying weaknesses, and improving defenses.

Related: What you need to know about log monitoring

Testing

Security testing validates whether an application’s defenses are working as expected. It helps identify vulnerabilities early, before attackers can exploit them.

Common security testing methods include:

• Static Application Security Testing (SAST): Analyzes source code for vulnerabilities without executing it
• Dynamic Application Security Testing (DAST): Examines running applications to identify exploitable weaknesses
• Interactive Application Security Testing (IAST): Offers real-time insights while the application is running

Through consistent testing, organisations can discover security flaws, fix issues promptly, and ensure that their applications remain resilient against evolving threats.

How Paubox ensures application security

Paubox takes a multi-layered approach to application (email) security, especially geared towards HIPAA-sensitive communications. Here’s how Paubox ensures application security:

Authentication

Paubox supports two-factor authentication (2FA) for user accounts. This adds an extra layer of security so that even if someone has a password, they still need a second factor to gain access. 

Authorization

Paubox gives administrators control over encrypted vs. unencrypted senders. In the Paubox dashboard (Outbound Security → Senders), admins can view and manage which email addresses are forced to use Paubox’s encryption. 

Furthermore, Paubox offers role-based control through its dashboard and Mail Log. Paubox provides audit and access controls so that not everyone has equal rights to release quarantined messages or view certain logs and settings. 

Encryption

Paubox enforces TLS 1.2 and TLS 1.3 for email in transit. This encryption is automatic for senders. According to their user guide, all outbound emails are encrypted by default; senders don’t need to do anything special. 

Additionally, Paubox provides a business associate agreement (BAA) to its customers, ensuring they are contractually bound to handle protected health information (PHI) securely. 

Logging

Paubox maintains mail logs that provide detailed records of email activity: who sent what, when, delivery status, and more. These logs support audit and compliance by helping organizations trace actions during a security incident, meet HIPAA requirements, and maintain visibility of system usage. 

Testing and threat detection

While Paubox doesn’t publicly describe traditional software-application-level testing (e.g., SAST), they have strong security features for threat detection and mitigation in their email application:

• AI-powered Inbound Email Security: Paubox uses generative AI to analyze tone, intent, and sender behaviour. It detects anomalies (like spoofing, phishing, or other malicious content) by comparing against historical patterns. 
• ExecProtect: This is a patented feature that defends against display name spoofing. This kind of spoofing is common in phishing attacks, where an attacker pretends to be a trusted person or department. 
• DomainAge: Paubox checks how recently a sending domain was registered. New domains are often used in phishing or spam attacks, so this helps block suspicious senders. 
• Virus and ransomware protection: Inbound emails are scanned for malware, viruses, and potentially dangerous attachments. Paubox claims to protect against ransomware and zero-day threats with behavioral and signature-based analysis. 
• GeoFencing and spam filtering: They provide geographical filtering (GeoFencing) to block emails from high-risk regions, plus customizable spam filters. 

Go deeper: Inbound Security: Overview

Additional security and compliance measures

• HITRUST CSF certification: Paubox’s Email Suite is HITRUST CSF certified, which is a strong external validation of their security controls. 
• Data Loss Prevention (DLP): Paubox has DLP controls to prevent sensitive data (PHI) from being accidentally or maliciously forwarded or leaked. 
• Email archiving: For compliance, Paubox supports secure email archiving, so all emails (with attachments) are stored in a way that can be audited later.

See also: HIPAA Compliant Email: The Definitive Guide (2025 Update)

FAQS

Who is responsible for application security?

Everyone involved in the application lifecycle shares responsibility: developers, security teams, DevOps engineers, administrators, and, in some cases, end users. 

How do vulnerabilities typically enter an application?

Vulnerabilities often come from insecure coding practices, outdated dependencies, misconfigurations, weak authentication, unvalidated user input, or insufficient testing before deployment.

How often should application security be reviewed?

Application security should be reviewed continuously, with scheduled audits, real-time monitoring, dependency scanning, and regular patching. Annual or ad-hoc reviews aren’t enough given evolving threats.