Why Some Websites Limit Password Symbols to Only Underscores and Hyphens

When creating a password, many websites impose strict rules that limit the use of certain symbols. Why is this the case, and what factors influence these rules? The answer lies in the policies set by website administrators, operating system limitations, and the need for secure password policies.

The Role of Website Administrators

Website administrators play a crucial role in determining password policies. They establish rules and guidelines based on company policy, security requirements, and technical limitations. These policies vary widely and can be influenced by a variety of factors, ranging from simple administrative choices to complex technical considerations.

Security and Input Filtering

All user inputs on a website, including passwords, need to be filtered for security. This process helps prevent potential security breaches. ‘_’ (underscore) and ‘-’ (hyphen) are considered safe for use because they are part of the standard alphanumeric character set, while other special characters require specific handling. If a website does not apply appropriate filters, it risks becoming a target for malicious activities.

Historical and Technical Constraints

In the past, certain characters were restricted due to their use in the operating system. For example, some characters such as ‘;’, ‘’, and ‘|’ were reserved for system commands. As operating systems have evolved, these restrictions have largely been lifted. However, some administrators might still impose these limitations due to a lack of technical knowledge or a preference for simpler rules.

The Importance of Password Policy Configuration

When setting up a server, administrators define security policies, which include password composition rules. Password composition typically falls into four categories: uppercase letters, lowercase letters, numbers, and special characters. The first step is to define what goes into each category. Generally, the letter and number sets are well-defined, but administrators need to decide which special characters to allow.

The best approach to password composition is to allow all possible special characters. This not only increases the complexity of passwords, making them more secure, but also provides users with more flexibility and control over their passwords.

Conclusion

Website administrators must carefully consider the security implications of password policies. Limiting the use of special characters to only underscores and hyphens might seem arbitrary, but it is often a reflection of historical limitations and current security best practices. By carefully considering password policies, administrators can ensure that their websites remain secure while providing a convenient user experience.

For more information on website security and password policies, visit the following resources:

Password Policy on Wikipedia Password Policy from Top Password Policies from SANS