Primality Certificate for (3284^2857-1)/3283

Andy Steward10,043 digits23 December 2006
Originally by A.A.D.Steward 2006

This certificate uses a theorem of Coppersmith and Howgrave-Graham to prove an integer N prime by making use of a partial prime factorization of N-1.

Factorizing N-1

As N is a Generalized Repunit, we make use of the algebraic factorization of N-1 to arrive at the following 29.602609% factorization of N-1:

From Factorisation
32842 · 2 · 821
Φ23 · 3 · 5 · 73
Φ3157 · 68713
Φ413 · 317 · 2617
Φ63 · 3593791
Φ77 · 29 · 43 · 1709 · 2731 · 45179 · 681689
Φ85881 · 6577 · 3007001
Φ12181 · 642590023501
Φ14113 · 491 · 953 · 23715584289503
Φ17137 · 1123 · 279311 · 2923559 · p40
Φ21673 · 1471 · 4831 · 228071155510087 · 1442016993355198891
Φ2447337337 · 285773112447063454153
Φ28449 · 196337 · 6810497 · 2620658572342713889636982081
Φ341718191 · 738956132922967 · 9414055107453013 · 15305633711655899537
Φ4211677 · 29947 · p34
Φ51103 · 135661 · 48846067 · 1689062955726733355023 · p77
Φ56281 · 156241 · 51973464516027601 · p61
Φ68907270757 · c104
Φ8443597 · 891577 · 513552746688682089634309 · p51
Φ1021531 · 269179 · 4447046287 · 75702659330629 · 7154003971248031 · 80028708682774302697 · p45
Φ11989665549 · c330
Φ136c226
Φ168337 · 52081 · c162
Φ204409 · 2795312041 · c213
Φ238239 · 35575051 · 236071249 · 509447482142697376060697699 · c293
Φ3575546305591 · c666
Φ40866442801 · 4807564481017 · c430
Φ4765167933 · 3512485546764906097 · 4282869062014933657 · c632
Φ71410711 · p672
Φ9522857 · 11724833 · 37513561 · 38356081 · 25485416993 · 160055723521 · 2761580292240231001 · p1285
Φ14281429 · 10327297 · 244040234613712153 · c1323
Φ2856108529 · c2696

We need the product F of all the prime factors from this partial factorization:

36647 8879788438 8421401921 5315835265 8055010211 0791931399 9647277635 6375938562 7743217488 4426016452 7506591809 9733778300 0272983887 2690342761 4832012935 3621610215 0338358375 9020973746 8784963257 0098478452 5563270286 6320393244 7478742403 1443254985 7240513355 2450391541 5364200728 6238810569 5597225294 5129269598 1507613523 5504362526 5814579249 8661758646 9975069062 2284075760 1637304170 7490071304 3430207717 1778473166 8815528056 0614163377 0686950726 7021770978 6630634633 3276083891 3143733825 7742758172 2800738164 7915036217 2207299972 1356069291 5656025262 6027085957 2607996597 2678983459 5416554610 3469337557 5822674470 9971359783 0418334854 0388777357 4332823670 3393960041 3040809719 7512443945 9117786464 4678346130 2663748156 9408019246 5512202040 3143406085 9501774260 7344314409 5384039078 8756581802 3400674703 1087322234 3861586781 3267407296 9664145392 8793257976 4616448582 6626885857 1270893651 2701480785 2381171377 0249711225 9818242153 6698352509 5113875350 8975980870 2413460873 4751803422 1681267297 3348714981 0479909000 0975967992 3147414860 4577783717 0861887660 1341778043 2718907288 8601306402 9740055529 9121159537 8022610478 4717127413 4596454690 5821262610 7890940723 8496130012 2333313411 0699586186 5451226344 9469631854 1540070149 2543485721 0097043300 3105780199 1886688814 9245140025 6457879713 5288744447 5866808777 4040336434 8398471286 2103575320 9387113337
13 1656485349 7889240698 2370570294 0450749826 3956049629 6460308237 7420251778 5468990551 1755533995 5096076521 8624941633 8154546906 9621435742 2042927727 4355588350 4950852447 7838614311 3928599072 0431003982 3912264277 9041035802 5007370955 5642664912 2157506297 5738046735 2213407919 4056041115 1925357323 0475826711 2583351721 6165158202 2141384998 4515868408 1649367581 4378162836 9418564797 5590533861 6834689240 6659071603 5223239041 4716233577 1988921962 0661713208 3535488029 9605369471 2291870297 5048718291 5739723302 8422125622 0649293964 0944528111 6865180437 7826699474 2842967626 2477294380 1712823352 2234637101 5968768678 2124165840 1490635698 0682797238 4305701723 8763848256 0988858513 1756361215 5865093245 5762881931
2904028 0564856336 4438763995 9440868911 4027642975 9045048441 2577162720 9102538147
1 0849071348 6396049770 2889662215 8113134005 7560255456 3589482761
1 2401524757 6020607618 1146031409 4302764895 2874292761
42173 4216213961 1890095465 4868820598 6664967169
1457076705 2947587252 0817684923 8505371879
4500 7553251533 7573614030 3170468539
26206585 7234271388 9636982081
5094474 8214269737 6060697699
5135 5274668868 2089634309
16 8906295572 6733355023
2 8577311244 7063454153
8002870868 2774302697
1530563371 1655899537
428286906 2014933657
351248554 6764906097
276158029 2240231001
144201699 3355198891
24404023 4613712153
5197346 4516027601
941405 5107453013
715400 3971248031
73895 6132922967
22807 1155510087
7570 2659330629
2371 5584289503
480 7564481017
64 2590023501
16 0055723521
2 5485416993
5546305591
4447046287
2795312041
907270757
236071249
89665549
66442801
48846067
47337337
38356081
37513561
35575051
11724833
10327297
6810497
5167933
3593791
3007001
2923559
1718191
891577
681689
279311
269179
196337
156241
135661
108529
68713
52081
45179
43597
29947
11677
10711
6577
5881
4831
2857
2731
2617
1709
1531
1471
1429
1123
953
821
673
491
449
409
337
317
281
239
181
157
137
113
103
73
43
29
13
7
5
33
22

Note that all prime factors listed above have been proven. As primes of under 250 decimal digits can be verified in a few seconds, proof of their primality is not included here, in order to save space. Larger prime factors can take from hours to months to prove; certificates for all such factors have been PKZIPped into this file.

We set R = (N-1)/F. Note that GCD(F,R)=1 and Log(F)/Log(N) = 29.602609%

Finding a Witness to Primality

Next, we find an integer witness w such that for each prime factor p of N-1, w(N-1) ≡ 1 mod N and GCD(w(N-1)/p-1,N) = 1. In this case, w = 418 suffices.

Given such a witness, Pocklington's Theorem shows that every prime factor of N ≡ 1 (mod F). As F4>N, N can have no more than three prime factors.

Express N in base F

As F2 < N < F3 and N ≡ 1 (mod F), we can let N = c2·F2 + c1·F + 1.

Brillhart, Lehmer and Selfridge

Brillhart, Lehmer and Selfridge's Theorem shows that N has exactly two prime factors if and only if c12-4·c2 is a perfect square.

Here, c12-4·c2 is ≡ 32 (mod 63) and therefore cannot be a square and this stage of the proof is passed.

Coppersmith and Howgrave-Graham

We are left with two possibilities for N: either it has exactly three prime factors or it is prime. The non-existence of exactly three factors is demonstrated by the Theorem of Coppersmith and Howgrave-Graham, here performed by a Pari/GP script written by John Renze and David Broadhurst. Here is the stdout:

realprecision = 3005 significant digits (3000 digits displayed)

Welcome to the CHG primality prover!
------------------------------------

Input file is:  IO\0CD40B29.cin
Certificate file is:  IO\0CD40B29.chg
Found values of n, F and G.
    Number to be tested has 10043 digits.
    Modulus has 2973 digits.
Modulus is 29.60260889% of n.

NOTICE: This program assumes that n has passed
    a BLS PRP-test with n, F, and G as given.  If
    not, then any results will be invalid!

Square test passed for F >> G.  Using modified right endpoint.

Search for factors congruent to 1.
    Running CHG with h = 6, u = 2. Right endpoint has 1125 digits.
        Done!  Time elapsed:  103938ms.
    Running CHG with h = 5, u = 1. Right endpoint has 908 digits.
        Done!  Time elapsed:  26828ms.
    Running CHG with h = 5, u = 1. Right endpoint has 824 digits.
        Done!  Time elapsed:  29875ms.
    Running CHG with h = 5, u = 1. Right endpoint has 657 digits.
        Done!  Time elapsed:  32718ms.
    Running CHG with h = 5, u = 1. Right endpoint has 322 digits.
        Done!  Time elapsed:  15719ms.
A certificate has been saved to the file:  IO\0CD40B29.chg

Running David Broadhurst's verifier on the saved certificate...

Testing a PRP called "IO\0CD40B29.cin".

Pol[1, 1] with [h, u]=[5, 1] has ratio=3.277324243 E-321 at X, ratio=5.254029306 E-643 at Y, witness=3.
Pol[2, 1] with [h, u]=[4, 1] has ratio=7.40368827 E-336 at X, ratio=3.978480043 E-335 at Y, witness=11.
Pol[3, 1] with [h, u]=[4, 1] has ratio=8.88972581 E-170 at X, ratio=6.393116952 E-168 at Y, witness=3.
Pol[4, 1] with [h, u]=[4, 1] has ratio=2.120579725 E-85 at X, ratio=2.587782524 E-84 at Y, witness=13.
Pol[5, 1] with [h, u]=[6, 2] has ratio=3.439276271 E-219 at X, ratio=4.863276572 E-435 at Y, witness=3.

Validated in 1 sec.


Congratulations! n is prime!

The actual input file containing N and F and the output certificate are included in this file.