Piñata Vision barcode/Obfuscation set

Note: Most of this article is speculation, and is unproven.

The Piñata Vision barcode article discusses obfuscation (of the barcode) in general.

Obfuscation sets

It's possible that the obfuscation set is identified by the first and last byte of the barcode's first (bottom) row. Having examined several sets for ID bits, each set with a common first and last byte seems to use the same columns for its obfuscated ID bits. (See the Choclodocus egg card article for an example of an obfuscation set's ID bit locations.)

Since the first and last byte of row 1 appears to be used for obfuscation, that leaves 56 bits for data (assuming the card only has one row).

Multi-row cards

It's unknown if each following row uses the same obfuscation, or whether or not all the following row's bits are dedicated to data. Further study should examine first and last bytes of row 2, to see if they happen to appear in the following table. If so, it might be possble that data is broken down into blocks of 56 bits, and obfuscated on a per-row basis.

Based on a glance at the leading and trailing byte of row 2, it doesn't seem to have anything in common with sets used by row 1. This makes sense, since a) it's more efficient to store/obfuscate 64 bits of useable data, and b) the data wouldn't call for additional overhead of a per-row obfuscation. Additional rows may solely contain data that's similarly obfuscated as row 1. (Has row 1's leading and trailing byte been obfuscated, or does row 1's obfuscation only involve the 56 data bits? Are all 64 bits of row 2 obfuscated, or are 63-60 and 03-00 in the clear?)

./obfuscation_sets.pl --row=2 --short
01 (3) 02 (1) 03 (2) 04 (1) 06 (1) 07 (2) 08 (2) 09 (2) 0A (2) 0B (1) 0D (2) 0E (2) 11 (2) 14 (1) 16 (2) 17 (2) 18 (3) 19 (2) 1A (1) 1B (1)
1C (2) 23 (1) 24 (1) 25 (1) 27 (1) 28 (1) 2C (3) 2D (4) 2E (2) 30 (1) 31 (1) 34 (1) 36 (2) 3A (1) 3C (4) 3D (2) 3E (5) 40 (2) 42 (2) 43 (6)
48 (3) 4A (1) 4B (4) 4F (2) 50 (1) 51 (3) 54 (1) 57 (1) 59 (2) 5A (4) 5B (2) 5D (2) 5E (2) 60 (1) 61 (5) 62 (1) 63 (5) 64 (1) 65 (5) 67 (2)
68 (3) 6D (1) 6E (2) 6F (2) 70 (1) 71 (1) 72 (1) 74 (1) 76 (1) 78 (1) 79 (1) 7A (1) 7B (1) 7C (1) 7F (1) 81 (5) 82 (2) 83 (3) 84 (12) 85 (25)
86 (11) 87 (18) 88 (29) 89 (1) 8A (15) 8B (26) 8D (4) 8E (3) 90 (2) 91 (2) 92 (1) 93 (3) 94 (16) 95 (11) 96 (14) 97 (4) 98 (10) 99 (43)
9A (22) 9C (9) 9F (1) A0 (4) A1 (3) A2 (15) A3 (46) A5 (14) A6 (4) A7 (14) A8 (4) A9 (13) AA (23) AC (1) AD (1) B1 (1) B2 (16) B3 (24)
B4 (2) B5 (3) B6 (31) B7 (7) B8 (2) B9 (3) BA (11) BB (39) BC (1) BD (1) BF (2) C0 (1) C1 (1) C2 (4) C3 (2) C4 (1) C5 (6) C6 (9) C7 (5)
C8 (1) C9 (14) CA (1) CC (33) CD (1) CE (19) CF (10) D2 (2) D3 (2) D4 (31) D5 (9) D6 (8) D7 (12) D8 (24) DB (2) DD (30) DE (12) DF (29)
E0 (68) E1 (29) E2 (28) E3 (3) E4 (17) E5 (4) E6 (7) E7 (1) E9 (1) EA (2) EC (29) EE (36) EF (9) F0 (7) F1 (33) F2 (5) F3 (2) F4 (9) F5 (1)
F6 (4) F7 (11) F8 (5) F9 (1) FA (1) FB (1) FC (1) FD (42) FE (3) FF (36)

./obfuscation_sets.pl --row=2 | wc -l
     182

Obfuscation set selection

The method of selecting an obfuscation for the card's data seems to involve the ID bits to some degree. See the ID table for a pattern/grouping of obfuscated cards. It's probable that not every type of card has an ID field, so one possibility is that the obfuscation is selected based on data that (directly?) follows the card type field, and that the ID field follows the card type field for certain types of cards.

Obfuscation method

It's not known yet if the obfuscation method is based on a formula (i.e., the different sets have a common method of obfuscation), or a lookup table (i.e., the different sets are independently obfuscated and have nothing in common).

96 and C6 ID bits are stored in the same columns. (See the Choclodocus egg card article for bit diff results.) Does this mean that both sets are obfuscated the same way, or that the leading byte is not (entirely) related to the obfuscation set key?

List of obfuscation sets

The set count is based on unique barcodes (no duplicates).

The TroubleInParadise cards are wiki cards, and are not broken down by card type.

Totaling the number of member cards may not match the count for various reasons:

• Duplicate cards (e.g., card known by two names, such as Vision_Single_Placetag_Egg_dog and Barkbark-TroubleInParadise-Egg)
• Omitted member cards (i.e., 010A22F91408B400D112.jpg from VivaPinata.com)

There appear to be 66 (out of a possible 8x16=128) obfuscation sets:

./obfuscation_sets.pl | wc -l
      66