In the second chapter of Hilchot Teshuva (Halacha 4), the Rambam (Rabbi Moshe Maimonides, Spain-Egypt, 1135-1204) describes the way a person should conduct himself as part of the process of repentance (listen to audio for precise citation). A penitent sinner should accustom himself to cry and pray to God for forgiveness, donate money to charity to the greatest possible extent, and distance himself from the matter regarding which he had committed the sin. Additionally, under certain circumstances it is advisable for a person to go so far as to change his name, in order to convey to himself the psychological message that he is no longer the same person as the one who had transgressed. Finally, the Rambam writes that "Galut," literally "exile" or relocation, is a beneficial means of atonement. Taking residence in a new area often has the effect of humbling and subduing one's character, and it is thus recommended under certain situations for sinners to relocate. It has been explained that this notion underlies the Misva to reside in a Sukka for a week after Yom Kippur. As part of our process of Teshuva, we leave the comfort and security of our homes and experience the instability of a Sukka, which causes us a sense of humility and helps us correct the flaws in our character.
In the next Halacha (5), the Rambam addresses the issue of whether it is appropriate to publicize one's sin in order to subject himself to shame as part of the Teshuva process. The Rambam distinguishes in this regard between offenses committed against one's fellow, and sins committed solely against the Almighty. In the case of interpersonal offenses, the Rambam rules that one should, in fact, publicly confess and express his contrition, and one who refuses to do so does not achieve complete Teshuva. When it comes, however, to sins committed solely against God, the Rambam writes that one should not make public mention of his sins, and publicizing one's sins against God is in fact deemed brazen. One may refer in a general sense in public to his having acted wrongly, but specifying one's sins in public is improper.
The Rambam's ruling is based upon the Gemara's discussion of this topic in Masechet Yoma. The Gemara cites two verses which appear to lead to conflicting conclusions; one verse indicates that publicizing one's sin is laudable, while the other advocates keeping this information private. The Gemara offers two approaches to reconcile these verses, one of which forms the basis of the Rambam's ruling, distinguishing between sins committed against God and interpersonal offenses. In addition, however, the Gemara suggests distinguishing between situations where the sin has already been made public, and cases where there is no public knowledge of the act. If the public is already aware of the sin, then the sinner should make public the fact that he regrets the act and has performed Teshuva. If, however, the sin has not been publicized, then one should not make it public as part of his repentance.
Accordingly, the Ra'avad (Rabbi Avraham Ben David of Posquieres, 1120-1198), in his critique of the Rambam's Mishneh Torah, notes that even if one committed a sin solely against God, he must publicly confess to his wrongdoing if the matter had already become public. Rabbi Yosef Karo (author of the Shulhan Aruch), in his Kesef Mishneh commentary, claimed that the Rambam held this opinion, as well, and that only in instances of sins committed against God and that have not been made public is it improper for one to publicly confess.
Summary: A penitent sinner should accustom himself to pray to God for forgiveness, give charity, distance himself from the matter regarding which he sinned, and, in some circumstances, even change his name and his location. It is proper to publicly confess one's sin, except in the case of a sin committed against God (as opposed to one's fellow man) that has not been made public.
