Maybe its time to explore raw ECDSA signed message based certs. btw I dont think its quite 4kB. eg bitpay's looks to be about 1.5kB in der format. And they contain a 2048-bit RSA server key, and 2048-bit RSA signatures (256byte each right there = 512bytes). And even 2048 is weaker than 256-bit ECDSA.
Adam On Fri, Mar 21, 2014 at 11:25:59AM +0100, Andreas Schildbach wrote: >On 03/20/2014 01:12 PM, Adam Back wrote: > >> Whats a sensible limit on practical/convenient QR code size? > >Technically 3 KB. In my experience codes above 1.5 KB become impossible >to scan (ZXing scanner, 3 years ago). You will want to stay below 500 >bytes for convenient scanning. That said, I'm convinced there is a lot >of room for scanning improvements. > >> How much of the payment protocol message size comes from use of x509? > >As said in the OP, a minimal PR uses 50 bytes. X.509 seems to put about >4000 bytes on top of that. > >As you can see, we have quite some room for improvements to PR payload >(PaymentDetails). X.509 certification will probably not be possible via >QR, at least not until specialized CA's will issue space-efficient certs >(using ECDSA?). ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development
