If the offender under a restitution system is unable to pay his debt out of his immediate resources, he is obliged to make payment through physical and/or mental labor, supplied over whatever period of time might be required. Security requirements may be imposed during this period, varying from maximum-security detention to minimal security (such as electronic bracelets) to no security at all, depending on the character of the offender. Where security was necessary, supervision of the offender might conceivably be contracted out to a private company. That company would pay the offender's debt to his victim(s) up front, recovering that cost afterward from the offender as efficiently as possible. If it is clear that the full debt cannot be recovered from the offender, perhaps because the offender's productive skills are minimal, then the recoverable amount might be determined by competitive bidding among such companies. In other cases, the full debt might be adjudged recoverable by more than one bidder; in such instances the offender himself might be permitted to choose the company through which he would provide repayment.