KDE PIM/KItinerary/Trenitalia Barcode

General Observations

• always 67 bytes
• exactly for one passenger/leg
• does not seem to contain signatures, checksums or compression, based on minimal bit pattern changes on adjacent tickets
• a lot less null bytes when PNR/seat reservation are present (ie. highspeed train tickets?)
• there is a unique, globally sequential ticket number, 2017 in the 600M range, 2019 in the 1B range, which suggests 32bit might be a bit short for this

Bit Layout

Byte:Bit (MSB)	Content	Meaning	Notes
0:0 - 4:7	0x20 0x14 0xC2 0x08 0x10	header?	fixed value in all samples
5:0 - 7:7		date?	varies between samples
8:0 - 13:4	null
13:5 - 14:3	100 xxxx		0000 for Italian stations codes (UIC 83.....), 0111 for international destination?
14:4 - 17:3	24 bit uint	UIC station code of departure	only for Italian destinations apparently
17:4 - 18:2	100 xxxx		see above
18:3 - 21:2	24 bit uint	UIC station code of arrival	see above
21:3 - 22:1		unknown	22:1 seems 0 in all samples, the rest varies
22:2 - 24:1	16 bit uint	train number	could be as little as 14 bits too, no train number > 16k has been observed
24:3 - 29:7	null
30:0 - 38:7			null if no PNR present, seems to contain seat number?
39:0 -42:7	null
40:0 - 50:7			null if no PNR present, unknown content otherwise
51:0 - 57:7	0x0B 0x65 0x23 0x18 0x40 0xE6 0xC0		fixed in all samples?
58:0 - 58:3	null		might be part of the ticket number?
58:4 - 62:3	32 bit uint	ticket number
63:4 - 65:7	null
66:0 - 66:7			varies between samples

Open Questions

• there is one sample where the departure and arrival UIC station codes are equal, contrary to what's in the corresponding PDF
• for international destinations the station code does not actually seem to be a valid UIC station code, but there is only one sample to back this up so far