I have a question... what happens if you derive at the same K value with different RSZ and on 254 and 256 bit...
is that not suppose to occur? does this allow the funds to be spent on the correlating address?
For a given pubkey, you will have four possible combos to make a different but equivalent signature for it: X and P-X (unless X >= N - an extremely rare occurence), and Y and -Y.
R is directly derived from X so the only way you'd end up with two R's for the same nonce is if you used the other identical value for X. In a similar vein, you can end up with four different S values if you mix&match X and Y values.
And yes, that would allow the private key to be solved for and its funds to be spent, because solving such an equation is trivial.
edit .... ok ok so the following example with K being the same; would not apply? is it R and S only or K also?
or
do they have
another K in common ?... as IF K were the same ; then R should be also?? Because r=k*G ??
Does the example here apply to it being solved?
i keep getting different answers ...
R = 2a6054e8ce59804ea0f17acd9bae77821979db060a68a00495478a131d1f2af4
S = 59ae683a16989880daeb3d5a51db290e0d5df58646096ba9b2f0aea0b3b653b4
Z = df1fef64c3e73a4da4bafe978a7972704ab1d3b00856b9781d766d0e2f88b39c
K = bc813ab951c818377c8ff62e231b513590eeac46209724e3ac3240b331e5e141 253 bits --- being the same
Z/(s-r) b0619c786326bac40967b8c05d8f059139b159774b97963fd9ba1b1a3f14783f
Z/S= 0ccff1a8a20c7894467fcfa5ea954551029b1fa53233d309bcf4cc4c8dc
R/S= 5db046ac0b085437a89db5d3fe929e2bffb2103a17583a1271821fc6734968ef
RS-ZS= 50e0550368fbdba3621de62e14021545235d0010655de6ef345183f72684a013
------------------------------------------------------------------------------
R = ff711fed4c0317d4801f3629032e058b9a071c9188faf3b9d774cb62e56283d0
S = 09bfa67778a2edea3476eb39ddf714b38453285615b738d2936408a80853f8d5
Z = 4c6e87c7ee7dcd84efc9d9db53dc54205018f8d283888ea3697700e4af9e
K = bc813ab951c818377c8ff62e231b513590eeac46209724e3ac3240b331e5e141 256 bits -- being the same
Z/(s-r) bc562f9ce5c0603eac439117824598c37b98ab4d0b0642bb73769f87f4de1169
Z/S= 0f5dee8376c61bd8a11c42b4f4f3e3d6f7be4025cba2fb9ce62b931b00440ec2
R/S= c41ad234c35db01fc5edb73b3792e275dcc31f152ea3de7a57056df491b9a777
RS-ZS= b4bce3b14c97944724d17486429ef4535432ee504deef6300e2dd70d9dad9917598b5
derived from Addresss and compressed pubkey
* this is just a example..
edit: does the bit value matter? what if they were 9bit instead? or has no bearing?