Vouchers and methods for providing vouchers configured to assist in distinguishing unauthorized duplicate or counterfeit vouchers are disclosed herein. In one embodiment, a voucher can include a substrate, a first indicia on the substrate, and a thermally responsive second indicia on the substrate. At least one of the first indicia and the second indicia can indicate a value of the voucher. A system which assists in detecting alteration of value documents or transmissions, such as a coin counter voucher is provided. Voucher information such as the voucher value is included in the voucher in an encrypted or otherwise modified form. When the voucher is presented for redemptions, the encrypted information is decrypted and compared to independently available voucher information. Failure of the information to match indicates that the voucher has been altered or should otherwise be further checked.