Encoding Table

PFPX Navdata files use a custom XOR-based encoding system. The navigation data is encoded using a character mapping table that transforms readable ASCII text into binary data.

Character Mapping

Through reverse engineering, we've determined the following encoding relationships:

Hex Code	Character	Hex Code	Character
A5	Space ()	B5	0
A4	!	B4	1
A7	"	B7	2
A6	#	B6	3
A1	$	B1	4
A0	%	B0	5
A3	&	B3	6
A2	'	B2	7
AD	(	BD	8
AC	)	BC	9
AF	*	BF	:
AE	+	BE	;
A9	,	B9	<
A8	–	B8	=
AB	.	BB	>
AA	/	BA	?

Hex Code	Character	Hex Code	Character
C5	@	D5	P
C4	A	D4	Q
C7	B	D7	R
C6	C	D6	S
C1	D	D1	T
C0	E	D0	U
C3	F	D3	V
C2	G	D2	W
CD	H	DD	X
CC	I	DC	Y
CF	J	DF	Z
CE	K	DE	[
C9	L	D9	\
C8	M	D8	]
CB	N	DB	^
CA	O	DA	_

Hex Code	Character	Hex Code	Character
E5	`	F5	p
E4	a	F4	q
E7	b	F7	r
E6	c	F6	s
E1	d	F1	t
E0	e	F0	u
E3	f	F3	v
E2	g	F2	w
ED	h	FD	x
EC	i	FC	y
EF	j	FF	z
EE	k	FE	{
E9	l	F9	|
E8	m	F8	}
EB	n	FB	~
EA	o	FA	DEL

Encoding Method

The encoding process works as follows:

1. XOR Operation: Each byte is XORed with the key 0x85
2. Character Mapping: The result maps to the above character table
3. Header Preservation: File headers remain in plaintext
4. Line Structure: Each line represents one navigation data entry

Key Properties

• XOR Key: 0x85 (decimal 133)
• Reversible: The same operation decodes the data
• ASCII Compatible: Maps to standard ASCII character set
• Binary Safe: Preserves data integrity

Usage Notes

Important

• Only the navigation data content is encoded
• File headers and metadata remain in plaintext
• Newline characters (CR/LF) are preserved during encoding
• The encoding is case-sensitive and position-dependent

Example Transformation

Here's a simple example of how a character gets encoded:

Original character: 'A' (ASCII 65, hex 0x41)
XOR with 0x85: 0x41 ^ 0x85 = 0xC4
Lookup in table: 0xC4 = 'A'

For the reverse (decoding):

Encoded byte: 0xC4
XOR with 0x85: 0xC4 ^ 0x85 = 0x41
ASCII result: 0x41 = 'A'

Next Steps

• Learn the decoding process - Apply this knowledge practically
• Use our Python tools - Automate encoding/decoding
• Understand file structure - See how encoded data is organized