The design of a secure RFID identification scheme is a thought-provoking challenge, and this paper deals with this problem adopting a groundbreaking approach. The proposed protocol, called Noent, is based on cryptographic puzzles to avoid the indiscriminate disclose of the confidential information stored on tags and on an innovative role reversal distance-bounding protocol to distinguish between honest and rogue readers. The protocol provides moderate privacy protection (data and location) to single tags but its effectiveness increases hugely when it is used to protect a large population of tags (e.g., protection against inventory disclosure). Moreover, in comparison with classical approaches, Noent does not require an online database, which facilitates key updating and mitigates desynchronization attacks.