The Line Oriented Searchable Encryption (LOE) scheme allows you to encrypt a line of text and still can search that field for exact keywords.
This scheme works by encrypting each character in a text field, plus the white space and any punctuation, with a header and a footer. For example, consider a sentence in a text field such as, “The little brown fox ran fast." The original number of characters including punctuation is 25. Using searchable encryption would add 25 + 6 x the header size + footer size. This doubles the length of the overall encryption.
LOE solves a problem that regular searchable encryption has with punctuation. For example, in the previous example sentence, the final word combines with the period, "fast." This makes "fast" alone unsearchable. LOE eliminates the extra period character as unnecessary and preserves searchability.
Use Case: Use Line Oriented Searchable Encryption for free text areas that you want to be encrypted, but still searchable. For example, if you had a notes field with data that included a secret project name such as, "Customer is interested in learning roadmap for <secret project name>." The secret project name would be encrypted, but users could still search for it. This scheme can also be used in fields that include PCI information, or other compliance standards.