Research of ID-Mask SIV Engine MAC & Randomization Byte Lengths.

mac-rnd-sizes.md

Proposed Lengths for ID Encryption Schema

32-bit Integer

Integer	Value	MAC	Version	Randomization	Sum	Base64/Base32
deterministic	4 byte	12 byte	1 byte	-	17 byte (136 bit)	22/27
randomized	4 byte	12 byte	1 byte	10 byte	27 byte (216 bit)	36/43

64-bit Integer

Long	Value	MAC	Version	Randomization	Sum	Base64/Base32
deterministic	8 byte	12 byte	1 byte	-	21 byte (168 bit)	28/33
randomized	8 byte	12 byte	1 byte	12 byte	33 byte (264 bit)	44/52

128-bit Integer

128-bit	Value	MAC	Version	Randomization	Sum	Base64/Base32
deterministic	16 byte	16 byte	1 byte	-	33 byte (264 bit)	44/52
randomized	16 byte	16 byte	1 byte	16 byte	49 byte (329 bit)	65/78

256-bit Integer

256-bit	Value	MAC	Version	Randomization	Sum	Base64/Base32
deterministic	32 byte	16 byte	1 byte	-	49 byte (329 bit)	65/78
randomized	32 byte	16 byte	1 byte	16 byte	65 byte (520 bit)	86/104

Birthday Problem Cheat Sheet

f=sqr(2*n*ln(1/1-p))
n.....number of possible values
p.....probability of finding a duplicate

prob of duplicate	0,1%	1,0%	25,0%	50,0%	75,0%	99,0%
1 bytes	7,16E-01	2,27E+00	1,21E+01	1,88E+01	2,66E+01	4,86E+01
2 bytes	1,15E+01	3,63E+01	1,94E+02	3,01E+02	4,26E+02	7,77E+02
4 bytes	2,93E+03	9,29E+03	4,97E+04	7,72E+04	1,09E+05	1,99E+05
6 bytes	7,50E+05	2,38E+06	1,27E+07	1,98E+07	2,79E+07	5,09E+07
7 bytes	1,20E+07	3,81E+07	2,04E+08	3,16E+08	4,47E+08	8,15E+08
8 bytes	1,92E+08	6,09E+08	3,26E+09	5,06E+09	7,15E+09	1,30E+10
9 bytes	3,07E+09	9,74E+09	5,21E+10	8,09E+10	1,14E+11	2,09E+11
10 bytes	4,92E+10	1,56E+11	8,34E+11	1,29E+12	1,83E+12	3,34E+12
11 bytes	7,87E+11	2,49E+12	1,33E+13	2,07E+13	2,93E+13	5,34E+13
12 bytes	1,26E+13	3,99E+13	2,14E+14	3,31E+14	4,69E+14	8,54E+14
14 bytes	3,22E+15	1,02E+16	5,47E+16	8,48E+16	1,20E+17	2,19E+17
15 bytes	5,16E+16	1,63E+17	8,75E+17	1,36E+18	1,92E+18	3,50E+18
16 bytes	8,25E+17	2,62E+18	1,40E+19	2,17E+19	3,07E+19	5,60E+19
20 bytes	5,41E+22	1,71E+23	9,17E+23	1,42E+24	2,01E+24	3,67E+24
22 bytes	1,38E+25	4,39E+25	2,35E+26	3,64E+26	5,15E+26	9,39E+26
24 bytes	3,54E+27	1,12E+28	6,01E+28	9,33E+28	1,32E+29	2,40E+29
28 bytes	2,32E+32	7,36E+32	3,94E+33	6,11E+33	8,65E+33	1,58E+34
32 bytes	1,52E+37	4,82E+37	2,58E+38	4,01E+38	5,67E+38	1,03E+39
36 bytes	9,98E+41	3,16E+42	1,69E+43	2,63E+43	3,71E+43	6,77E+43
40 bytes	6,54E+46	2,07E+47	1,11E+48	1,72E+48	2,43E+48	4,44E+48
48 bytes	2,81E+56	8,90E+56	4,76E+57	7,39E+57	1,05E+58	1,91E+58
56 bytes	1,21E+66	3,82E+66	2,04E+67	3,17E+67	4,49E+67	8,18E+67
64 bytes	5,18E+75	1,64E+76	8,78E+76	1,36E+77	1,93E+77	3,51E+77
72 bytes	2,22E+85	7,05E+85	3,77E+86	5,86E+86	8,28E+86	1,51E+87
80 bytes	9,55E+94	3,03E+95	1,62E+96	2,51E+96	3,56E+96	6,48E+96
96 bytes	1,76E+114	5,59E+114	2,99E+115	4,64E+115	6,56E+115	1,20E+116
112 bytes	3,25E+133	1,03E+134	5,51E+134	8,56E+134	1,21E+135	2,21E+135

Current Applications

Google Photos

Creates shared link album with 70 char length (probably Base64-url) e.g.:

https://photos.google.com/share/CF111pMluO7DxBtyDDZl731xn_pX-Nk_N4bZrz-B3dopWdpV-Ozc59Kmy2blFe14IeRB2H

Alternative this 17 char Base64 string:

https://photos.app.goo.gl/Vyxy4gr1nQCXe9iTA

Youtube

Creates video link slugs with length ~11 chars

https://youtu.be/eCm5fiRniXc

Playlist use 34 char links

https://www.youtube.com/playlist?list=PLMC9KNkIncKtGvr2kFRuXBVmBev6cAJ2u

Github: Gist

Uses 32 char hex string for as id (also decimal found)

https://gist.github.com/cryptix/87127f76a94183747b53

Doodle

A inviation Link has 16 chars of probably base36 or base32 encoding.

https://doodle.com/poll/a2scup5d2kbe1dpf

Misc

BaseX Encoding Length Calculation

• Base64: 4*(n/3)
• Base32: n * 8 / 5