Untangling RFID Privacy Models

Box 3

Experiment Exp^{𝖩𝖶-𝗉𝗋𝗂𝗏}_𝒮,𝒜[𝜆,𝑛,𝜌,𝜎,𝜏]

Setup:

(1) 𝒞 initializes the system 𝒮.

Phase 1 (Learning):

(2) 𝒜 may do the following in any interleaved order:

 (a) Make LAUNCH and TAGINIT queries, without exceeding 𝜌 and 𝜏 overall queries respectively.

 (b) Make arbitrary SETKEY queries to any (𝑛−2) tags.

 (c) Make SENDREADER and SENDTAG queries, without exceeding 𝜎 overall queries.

Phase 2 (Challenge):

(3) 𝒜 selects two challenge tags 𝒯_𝑖 and 𝒯_𝑗 to which it did not send SETKEY queries.

(4) Let 𝒯^∗₀=𝒯_𝑖 and 𝒯^∗₁=𝒯_𝑗, and remove both from the current tag set.

(5) 𝒞 chooses a bit 𝑏 at random, and provides 𝒜 access to 𝒯^∗_𝑏.

(6) 𝒜 may do the following in any interleaved order:

 (a) Make LAUNCH and TAGINIT queries, without exceeding 𝜌 and 𝜏 overall queries respectively.

 (b) Make arbitrary SETKEY queries to any tag in the current tag set, except 𝒯^∗_𝑏.

 (c) Make SENDREADER and SENDTAG queries, without exceeding 𝜎 overall queries.

(7) 𝒜 outputs a guess bit 𝑏^′.

Exp^{𝖩𝖶-𝗉𝗋𝗂𝗏}_𝒮,𝒜 succeeds if 𝑏=𝑏^′.