The phrase "confidential basis" means that information or discussions should be kept private and not shared with others without permission. Full definition
For example, a new feature in Box Governance automatically classifies certain documents as confidential based on whether they contain private information such as personal health information, social security numbers, or credit card numbers, according to the company. (inc.com)
Any material non-public information may be kept confidential based on a «legitimate interest» of the company, except in cases of leakage of the information or unusual fluctuation of the public quotation, price or volume of a security issued by the company. (globalinvestigationsreview.com)
We may also supply the information you provide, on a strictly confidential basis, to service providers, such as title companies, appraisers, credit reporting services, etc., who assist us in qualifying, processing, closing and servicing your loan. (crosscountrymortgage.com)