[Bitcoin-development] Signature with negative integer?

Richard Moore me at ricmoo.com
Sat Jul 19 04:33:13 UTC 2014

```Hey all,

I'm wondering if anyone can help explain to me tx 70f7c15c6f62139cc41afa858894650344eda9975b46656d893ee59df8914a3d...

(https://blockchain.info/tx/70f7c15c6f62139cc41afa858894650344eda9975b46656d893ee59df8914a3d)

The input signature script is:

304402206b5c3b1c86748dcf328b9f3a65e10085afcf5d1af5b40970d8ce3a9355e06b5b0220cdbdc23e6d3618e47056fccc60c5f73d1a542186705197e5791e97f0e6582a3201

Which decodes to:

r= 48560432700441876832361368709121298776045893858160378595187765610521057848155
s= -22732680560694206332190468058638664750027418114195068375538144640549433890254

(http://lapo.it/asn1js/#304402206B5C3B1C86748DCF328B9F3A65E10085AFCF5D1AF5B40970D8CE3A9355E06B5B0220CDBDC23E6D3618E47056FCCC60C5F73D1A542186705197E5791E97F0E6582A32)

The ECC library I'm using is failing to verify this, which I think makes sense, since I the point needs to be positive, no? But it is obviously valid, as it has been verified and spent. I have tried simply modulo curve.order to positive-ify it, but that didn't seem to work either. Given a point P (with Py < 0) is there some fancy way to bring it into the elliptic curve space, such that Px >= 0 and Py >= 0?

Thanks!

RicMoo

.·´¯`·.¸¸.·´¯`·.¸¸.·´¯`·.¸¸.·´¯`·.¸¸.·´¯`·.¸><(((º>

Richard Moore ~ Founder
Genetic Mistakes Software inc.
phone: (778) 882-6125
email: ricmoo at geneticmistakes.com
www: http://GeneticMistakes.com

```