Facilitating the purchase and sale of private data between anonymous entities based on the use of encryption and a centralized on-line entity to exchange the private data in a secure environment. The seeker of private data, such as consumer information, transmits an encrypted query to the centralized exchange entity. The query submission includes legal representations stating the legally permissible purpose for seeking the information. The centralized exchange entity compares the encrypted query to an encrypted data index collected from at least one data provider, to determine if the query matches any private data held by a data provider. The comparison is conducted within a secure, search component to ensure the privacy of all data and all parties to the transaction. The exchange entity facilitates the anonymous exchange between the data purchaser and the data provider. A payment invoice can be generated and electronically presented by maintainer. The payment may be electronically debited from the designated account of a data purchaser and remitted to a data provider. In addition, a portion of such funds may be retained by the centralized exchange entity.