Which of the following is NOT a characteristic of a secure password?

A secure password is characterized by traits that make it difficult for unauthorized users to guess or crack. Using easily guessable information, such as names, birthdays, or common phrases, significantly weakens a password's effectiveness. This kind of information is often readily available or can be easily deduced, making it a poor choice for security.

In contrast, using combinations of letters and numbers, incorporating special characters, and ensuring that the password has a substantial length (greater than 12 characters) all contribute to a higher level of security. These practices add complexity and variability, which make it more challenging for someone to successfully guess or brute-force their way into an account. Therefore, easily guessable information is the least secure approach when creating a password and stands out as the correct answer in this context.