AES (Advanced Encryption Standard) for the HP-42S

This program is by Brett Stevens and is used here by permission.

This program is supplied without representation or warranty of any kind. Brett Stevens and The Museum of HP Calculators therefore assume no responsibility and shall have no liability, consequential or otherwise, of any kind arising from the use of this program material or any part thereof.

Overview

An implementation of the Advanced Encryption Standard for the HP-42S calculator.

What follows is a description of how to implement the AES (Rijndael) ciphersystem on the HP42S.

Copyright 2001 Brett Stevens
School of Mathematics and Statistics
Carleton University
1125 Colonel By Dr.
Ottawa ON K1S 5B6
Canada
Phone: (613) 520-2600 x2125
FAX: (613) 520-3536
brett@math.carleton.ca
http://mathstat.carleton.ca/~brett/

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Note: ROTXY is a HP-42S command that rotates bits.

Set SIZE to 154

Place the following numbers in registers 00-63

Place the following numbers in registers 90 through 153

The following are the encryption and decryption programs and their procedures:

Listing

LBL "RJN"
1
STO 88
0
STO 89
72.075
STO 81
LBL 01
RCL 81
IP
RCL IND ST X
RCL 81
IP
4
+
R↓
STO IND ST T
ISG 81
GTO 01
XEQ "AKR"
XEQ "EXK"
0.008
STO 86
LBL 02
XEQ "SBX"
XEQ "SHR"
XEQ "MXC"
XEQ "AKR"
XEQ "EXK"
ISG 86
GTO 02
XEQ "SBX"
XEQ "SHR"
XEQ "AKR"
68.071
STO 88
0
LBL 03
RCL 88
IP
R↓
STO IND ST T
ISG 88
GTO 03
76.087
STO 88
0
LBL 04
RCL 88
IP
R↓
STO IND ST T
ISG 88
GTO 04
0
STO 88
STO 89
CLST
END


LBL "AKR"
0.003
STO 84
LBL 01
RCL 84
IP
64
+
RCL IND ST X
RCL 84
IP
76
+
R↓
RCL IND ST T
XOR
STO IND ST Y
ISG 84
GTO 01
END 


LBL "EXK"
0.003
STO 84
LBL 02
RCL 84
IP
80
+
STO 87
1
-
RCL IND ST X
STO 68
RCL 87
4
MOD
X=0?
XEQ 03
RCL 87
4
-
RCL IND ST X
RCL 68
XOR
RCL 87
4
-
R↓
STO IND ST T
RCL 87
R↓
STO IND ST T
ISG 84
GTO 02
RTN
LBL 03
RCL 68
255
AND
-24
ROTXY
STO 69
RCL 68
8
ROTXY
16777215
AND
RCL 69
XOR
STO 68
0
STO 69
0.003
STO 85
LBL 04
RCL 68
255
RCL 85
IP
8
x
STO 70
+/-
ROTXY
AND
RCL 70
ROTXY
XEQ "LKP"
RCL 70
+/-
ROTXY
RCL 69
XOR
STO 69
ISG 85
GTO 04
RCL 69
RCL 88
XOR
STO 68
RCL 88
-1
ROTXY
8
BIT?
XEQ 05
R↓
255
AND
STO 88
RTN
LBL 05
R↓
27
XOR
ENTER
RTN
END


LBL "IXK"
0.003
STO 84
LBL 01
RCL 84
IP
76
+
RCL IND ST X
RCL 84
IP
80
+
R↓
STO IND ST T
ISG 84
GTO 01
0
STO 89
0.003
STO 84
LBL 02
79
RCL 84
IP
-
STO 87
3
+
RCL IND ST X
STO 68
RCL 87
4
MOD
X=0?
XEQ 03
RCL 87
4
+
RCL IND ST X
RCL 68
XOR
RCL 87
R↓
STO IND ST T
ISG 84
GTO 02
90 
STO 89
RTN
LBL 03
RCL 68
255
AND
-24
ROTXY
STO 69
RCL 68
8
ROTXY
16777215
AND
RCL 69
XOR
STO 68
0
STO 69
0.003
STO 85
LBL 04
RCL 68
255
RCL 85
IP
8
x
STO 70
+/-
ROTXY
AND
RCL 70
ROTXY
XEQ "LKP"
RCL 70
+/-
ROTXY
RCL 69
XOR
STO 69
ISG 85
GTO 04
RCL 69
RCL 88
XOR
STO 68
RCL 88
1
ROTXY
35
BIT?
XEQ 05
R↓
255
AND
STO 88
RTN
LBL 05
R↓
-34359738227
XOR
ENTER
RTN
END


LB "MXC"
0.003
STO 80
LBL 01
0
STO 82
64
RCL 80
IP
+
STO 69
RCL IND 69
65535
-16
ROTXY
AND
16
ROTXY
RCL IND 69
XOR
ENTER
ENTER
255
-8
ROTXY
AND
8
ROTXY
XOR
255
AND
STO 68
0.003
STO 81
LBL 02
RCL 81
IP
8
x
STO 71
RCL IND 69
255
RCL 71
+/-
ROTXY
AND
RCL 71
ROTXY
STO 70
RCL IND 69
255
RCL 71
8
+
32
MOD
+/-
ROTXY
AND
RCL 71
8
+
32
MOD
ROTXY
RCL 70
XOR
XEQ 03
RCL 68
XOR
RCL 70
XOR
RCL 71
+/-
ROTXY
RCL 82
XOR
STO 82
ISG 81
GTO 02
RCL 82
STO IND 69
ISG 80
GTO 01
0
STO 69
STO 68
STO 70
STO 82
RTN
LBL 03
-1
ROTXY
8
BIT?
XEQ 04
R↓
255
AND
RTN
LBL 04
R↓
27
XOR
ENTER
RTN
END


LB "IMXC"
0.003
STO 80
LBL 01
0
STO 82
64
RCL 80
IP
+
STO 69
RCL IND 69
4294901760
AND
16
ROTXY
RCL IND 69
XOR
ENTER
ENTER
65280
AND
8
ROTXY
XOR
255
AND
STO 68
XEQ 03
XEQ 03
XEQ 03
RCL 68
XOR
STO 68
0.003
STO 81
LBL 02
RCL 81
IP
8
x
STO 71
RCL IND 69
255
RCL 71
+/-
ROTXY
AND
RCL 71
ROTXY
STO 70
RCL IND 69
255
RCL 71
16
+
32
MOD
+/-
ROTXY
AND
RCL 71
16
+
32
MOD
ROTXY
RCL 70
XOR
XEQ 03
STO 70
RCL IND 69
255
RCL 71
+/-
ROTXY
AND
RCL 71
ROTXY
RCL 70
XOR
STO 70
RCL IND 69
255
// ENTER  ??
RCL 71
8
+
32
MOD
+/-
ROTXY
AND
RCL 71
8
+
32
MOD
ROTXY
RCL 70
XOR
XEQ 03
RCL 68
XOR
RCL IND 69
255
RCL 71
+/-
ROTXY
AND
RCL 71
ROTXY
XOR
RCL 71
+/-
ROTXY
RCL 82
XOR
STO 82
ISG 81
GTO 02
RCL 82
STO IND 69
ISG 80
GTO 01
0
STO 69
STO 68
STO 70
STO 82
RTN
LBL 03
-1
ROTXY
8
BIT?
XEQ 04
R↓
255
AND
RTN
LBL 04
R↓
27
XOR
ENTER
RTN
END


LBL "SHR"
0
STO 68
STO 69
STO 70
STO 71
0.003
STO 80
LBL 01
0.003
STO 81
LBL 02
RCL 80
RCL 81
+
IP
4
MOD
64
+
RCL IND ST X
255
RCL 81
IP
8
x
+/-
ROTXY
AND
RCL 80
IP
68
+
STO 82
R↓
RCL IND 82
XOR
STO IND 82
ISG 81
GTO 02
ISG 80
GTO 01
0.003
STO 80
LBL 03
RCL 80
IP
64
+
ENTER
ENTER
4
+
RCL IND ST X
STO IND ST Z
ISG 80
GTO 03
END


LBL "SBX"
0.003
STO 80
LBL 01
0
STO 71
64
RCL 80
IP
+
STO 69
0.003
STO 81
LBL 02
RCL IND 69
255
RCL 81
IP
8
x
STO 70
+/-
ROTXY
AND
RCL 70
ROTXY
XEQ "LKP"
RCL 70
+/-
ROTXY
RCL 71
XOR
STO 71
ISG 81
GTO 02
RCL 71
STO IND 69
ISG 80
GTO 01
END


LBL "LKP"
ENTER
ENTER
4
MOD
X⇔Y
4
÷
IP
RCL 89
+
RCL IND ST X
X⇔Y
R↓
X⇔Y
8
x
STO ST Z
255
X⇔Y
+/-
ROTXY
AND
X⇔Y
ROTXY
END


LBL "IRJN"
1
STO 88
90
STO 89
72.075
STO 81
LBL 01
RCL 81
IP
RCL IND ST X
RCL 81
IP
4
+
R↓
STO IND ST T
ISG 81
GTO 01
0.009
STO 86
LBL 05
XEQ "EXK"
ISG 86
GTO 05
54
STO 88
XEQ "AKR"
XEQ "IXK"
0.008
STO 86
LBL 02
XEQ "SBX"
XEQ "SHR"
XEQ "SHR"
XEQ "SHR"
XEQ "ARK"
XEQ "IXK"
XEQ "IMXC"
ISG 86
GTO 02
XEQ "SBX"
XEQ "SHR"
XEQ "SHR"
XEQ "SHR"
XEQ "AKR"
68.071
STO 88
0
LBL 03
RCL 88
IP
R↓
STO IND ST T
ISG 88
GTO 03
76.087
STO 88
0
LBL 04
RCL 88
IP
R↓
STO IND ST T
ISG 88
GTO 04
0
STO 88
STO 89
CLST
END

License for "AES (advanced Encryption Standard) for the HP-42S"

The following license applies only to the "AES (advanced Encryption Standard) for the HP-42S" program listed above. It does not apply to other pages and programs on this website, except where specifically indicated.

GNU GENERAL PUBLIC LICENSE

Version 2, June 1991

59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.

Preamble

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GNU GENERAL PUBLIC LICENSE

TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

0. This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The "Program", below, refers to any such program or work, and a "work based on the Program" means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is included without limitation in the term "modification".) Each licensee is addressed as "you".

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1. You may copy and distribute verbatim copies of the Program's source code as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any other recipients of the Program a copy of this License along with the Program.

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Also add information on how to contact you by electronic and paper mail.

If the program is interactive, make it output a short notice like this when it starts in an interactive mode:

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The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program.

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<signature of Ty Coon>, 1 April 1989
Ty Coon, President of Vice

This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License instead of this License.

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