1. A method for conducting a transaction, comprising: generating, by a portable consumer device, a verification value in response to a transaction involving an access device; sending, by the portable consumer device, the verification value and a portion of a first dynamic data element to the access device, the portion of the first dynamic data element including data included in a fixed position of the first dynamic data element, the verification value being different from the portion of the first dynamic data element; and communicating, by the access device, the verification value and the portion of the first dynamic data element to a service provider computer; wherein the service provider computer determines a plurality of candidate dynamic data elements using the portion of the first dynamic data element in response to determining that the verification value does not match a second verification value independently generated by the service provider computer, determines a plurality of candidate verification values from the plurality of candidate dynamic data elements, and determines whether the verification value matches any of the plurality of candidate verification values; wherein, each of the plurality of candidate verification values is unique to a corresponding candidate dynamic data element of the plurality of candidate dynamic data elements; and wherein the transaction is thereafter authenticated when the verification value matches any of the plurality of candidate verification values.