rskeygen(1)						      General Commands Manual						       rskeygen(1)

NAME

       rskeygen - generate private key pairs for TI graphing calculators

SYNOPSIS

       rskeygen [ --secure ] [ --ti ] [ --length nbytes ]

DESCRIPTION

       rskeygen  generates application and OS signing keys for the Texas Instruments TI-73, TI-83 Plus, TI-84 Plus, TI-89, and TI-92 Plus graphing
       calculators.  These keys consist of two prime numbers p and q as well as their product n.  Current calculator models impose a limit of  512
       bits  (64  bytes)  on the size of n, so p and q are generally about 256 bits each.  As of this writing this means factoring n is beyond the
       reach of most people, though this will undoubtedly change in the future.

       The keys generated by rskeygen are not very useful at the moment, because in order for an application or OS to be accepted by the  calcula-
       tor,  the  key  used  to sign it must itself be signed using the calculator's own (possibly unique) private key, which is only known to TI.
       Nevertheless, rskeygen is provided in the hope that it can be useful, both for testing and for devising	new  signature	schemes  based	on
       TI's.

   OPTIONS
       --secure
	      Attempt  to  generate  a	``secure''  key using the system's entropy pool, /dev/random (see random(4).)  The actual security is thus
	      dependent on your system's implementation of /dev/random.

	      Without --secure, the keys are generated based on the current time and process ID, which is not secure in the slightest.

       --ti   Generate keys which are palatable to TI's official app signing programs.	This forces p to be congruent to 3 and q to  7	modulo	8.
	      This option is not necessary when using rabbitsign(1), nor is it necessary for the calculator to validate signatures properly.

       --length nbytes
	      Specify  the length in bytes of the modulus n; p and q are each calculated to be approximately half this length.	This should not be
	      greater than 64 for current calculators, and must be less than 256 in any event due to a limitation of the key file format.

SEE ALSO

       rabbitsign(1), packxxk(1)

AUTHOR

       Benjamin Moody <floppusmaximus@users.sf.net>

RabbitSign 2.0							     July 2009							       rskeygen(1)