Title
Parent-identifying codes
Abstract
For a set C of words of length 4 over an alphabet of size n , and for a ,  b ∈ C , let D ( a ,  b ) be the set of all descendants of a and b , that is, all words x of length 4 where x i ∈{ a i ,  b i } for all 1⩽ i ⩽4. The code C satisfies the Identifiable Parent Property if for any descendant of two code-words one can identify at least one parent. The study of such codes is motivated by questions about schemes that protect against piracy of software. Here we show that for any ε >0, if the alphabet size is n > n 0 ( ε ) then the maximum possible cardinality of such a code is less than εn 2 and yet it is bigger than n 2− ε . This answers a question of Hollmann, van Lint, Linnartz, and Tolhuizen. The proofs combine graph theoretic tools with techniques in additive number theory.
Year
DOI
Venue
2001
10.1006/jcta.2001.3177
J. Comb. Theory, Ser. A
Keywords
Field
DocType
parent-identifying code
Discrete mathematics,Graph,Combinatorics,Descendant,Cardinality,Identifiable parent property,Mathematical proof,Code (cryptography),Mathematics,Additive number theory,Alphabet
Journal
Volume
Issue
ISSN
95
2
Journal of Combinatorial Theory, Series A
Citations 
PageRank 
References 
10
0.99
3
Authors
3
Name
Order
Citations
PageRank
Noga Alon1104681688.16
eldar fischer281563.82
Mario Szegedy33358325.80