February 6, 2006 The cardinality of the curve E: Y^2 = X^3+4589*X+91128 modulo (p=10^2099+6243) is p+1-t with t= 46309039515660266466504436829543902982037303111273 73133329015939600620473192265145917348534609271301 80463487786678542979959407234769815726981464645620 45942259943796863867474309156215573353558251312947 05279002886049129524152450854617338507270325443970 45009251083206675470344648078432773977487544433481 80799415881345112208263533866935960995501879593481 23563494292428730241372116337183868845956990766720 16762883130518896917848778957234951929827379632139 23336753918213564996900545193436665475820821636114 40351895261067767318730922734900512756008172744976 01902169276283488975926314494300515154111433860489 79698992682115877314851670619809465979774090915096 58990522856709034389876336674924978610876297672927 22366580514359521188254467575882285940677159779534 48091024653607152243664910219594822529312596688627 12674193865426844485114378638574361621622675608807 03434187870680581930897304946865615024745778306695 51482064698450271097057130249581451860620439840908 82472930864017990614559843280193688352934271319965 36691264709607426192741260260055570692444330408489 Here are the timings on an AMD 64 Processor 3400+ (2.4GHz), with our NTL implementation, for some large numbers (excluding the time for computing modular equations): what | 500dd | 1000dd | 1500dd | 1600dd | 1700dd | 2005dd | 2100dd -------------------------------------------------------------------- X^p | 6h | 134h | 35d | 46d | 60d | 133d | 121d Total | 10h | 180h | 77d | 63d | 80d | 195d | 190d AEnge, PGaudry and FMorain