# Identifiable parent property (IPP) code[1]

## Description

A code that is embedded in copyrighted content in order to detect unauthorized redistribution of said content by pirates. IPP codes are designed to detect pirates even when segments content are mixed together so as to conceal the pirates' identities.

A unique codeword of an IPP code is hidden into each copy of the content (say, a movie or videogame) such that reselling a copy would expose the seller as a pirate.

To overcome this, a coalition of \(t\) pirates can mix their copies together so as to obfuscate their identities. The descendant bit-string corresponding to the new mixed copy therefore contains subsets of codeword coordinates of the copies that were used in the mixing.

More technically, let \(B=\{c_1 \cdots c_t\}\) be a subset of \(t\) IPP codewords, corresponding to the copies of the pirate coalition. Then, \(a\) is called a descendant of \(B\) if every coordinate of \(a\) also exists as a coordinate (in the same position) of at least one of the codewords in \(B\). In other words, for all coordinates \(i\), we require that \(a_i = c_i\) and some \(c \in B\).

A \(t\)-IPP code has the ability that, given any descendent, a parent codeword can always be identified by examining all possible \(t\)-subsets of the code [2].

## Rate

## Parent

- Frameproof (FP) code — A \(t\)-IPP code is a \(t\)-SFP code, which further implies it is a \(t\)-FP code; see [2][4; Sec. I.C].

## Child

- Traceability code — Traceability codes allow for detection of parents of pirated descendant copies by only determining the closest codeword to the descendant; see [4; Lemma 1.3].

## References

- [1]
- H. D. L. Hollmann et al., “On Codes with the Identifiable Parent Property”, Journal of Combinatorial Theory, Series A 82, 121 (1998) DOI
- [2]
- R. Ahlswede and N. Cai, “Codes with the identifiable parent property and the multiple–access channel”, Electronic Notes in Discrete Mathematics 21, 143 (2005) DOI
- [3]
- A. Barg et al., “A Hypergraph Approach to the Identifying Parent Property: The Case of Multiple Parents”, SIAM Journal on Discrete Mathematics 14, 423 (2001) DOI
- [4]
- J. N. Staddon, D. R. Stinson, and Ruizhong Wei, “Combinatorial properties of frameproof and traceability codes”, IEEE Transactions on Information Theory 47, 1042 (2001) DOI

## Page edit log

- Fengxing Zhu (2024-03-16) — most recent
- Victor V. Albert (2024-03-16)
- Victor V. Albert (2022-03-01)

## Cite as:

“Identifiable parent property (IPP) code”, The Error Correction Zoo (V. V. Albert & P. Faist, eds.), 2024. https://errorcorrectionzoo.org/c/ipp