A system accesses a task log comprising text that is confidential information. The system selects a first portion of the task log. The system compares each word in the first portion with keywords that are known to be confidential information. The system determines that a word in the first portion is among the keywords. The system determines a hierarchical relationship between the word and neighboring words. The system determines that the word is associated with the neighboring words based on the hierarchical relationship. The system generates a template pattern comprising the word and one or more words associated with the word. The system obfuscates the template pattern.