On the relationship between the traceability properties of Reed-Solomon codes

Fingerprinting codes are used to prevent dishonest users (traitors) from redistributing digital contents. In this context, codes with the traceability (TA) property and codes with the identifiable parent property (IPP) allow the unambiguous identification of traitors. The existence conditions for IPP codes are less strict than those for TA codes. In contrast, IPP codes do not have an efficient decoding algorithm in the general case. Other codes that have been widely studied but possess weaker identification capabilities are separating codes. It is a well-known result that a TA code is an IPP code, and an IPP code is a separating code. The converse is in general false. However, it has been conjectured that for Reed-Solomon codes all three properties are equivalent. In this paper we investigate this equivalence, providing a positive answer when the number of traitors divides the size of the ground field.