What should you do if you have taken the right of someone who is too shy to be approached and whom you fear to tell, and you want his forgiveness? And is someone considered a حافظ للقرآن (Hāfiz of the Qur'an) if he reviews a hizb daily but can only correct a few mistakes of readers, and what is the path to mastery?

For a repentance to be valid concerning a sin that infringes upon the right of a human being, the right must be returned to them or their forgiveness sought. It is sufficient to return the right by any means without informing them of the sin. As for the Qur’an, one must be diligent in solidifying what has been memorized by frequent revision, lest the Book of Allah slip away.