mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

, the RSA numbers are a set of large

semiprimes In mathematics, a semiprime is a natural number that is the product of exactly two prime numbers. The two primes in the product may equal each other, so the semiprimes include the squares of prime numbers. Because there are infinitely many prime n ...

(numbers with exactly two

prime factor A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways ...

s) that were part of the

RSA Factoring Challenge The RSA Factoring Challenge was a challenge put forward by RSA Laboratories on March 18, 1991 to encourage research into computational number theory and the practical difficulty of factoring large integers and cracking RSA keys used in cryptogr ...

. The challenge was to find the prime factors of each number. It was created by RSA Laboratories in March 1991 to encourage research into

computational number theory In mathematics and computer science, computational number theory, also known as algorithmic number theory, is the study of computational methods for investigating and solving problems in number theory and arithmetic geometry, including algorithm ...

and the practical difficulty of factoring large

integer An integer is the number zero (), a positive natural number (, , , etc.) or a negative integer with a minus sign ( −1, −2, −3, etc.). The negative numbers are the additive inverses of the corresponding positive numbers. In the languag ...

s. The challenge was ended in 2007. RSA Laboratories (which is an

acronym An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in ''NATO'' (''North Atlantic Treaty Organization''), but sometimes use syllables, as ...

of the creators of the technique; Rivest, Shamir and Adleman) published a number of semiprimes with 100 to 617

decimal The decimal numeral system (also called the base-ten positional numeral system and denary or decanary) is the standard system for denoting integer and non-integer numbers. It is the extension to non-integer numbers of the Hindu–Arabic numeral ...

digits. Cash prizes of varying size, up to US$200,000 (and prizes up to $20,000 awarded), were offered for factorization of some of them. The smallest RSA number was factored in a few days. Most of the numbers have still not been factored and many of them are expected to remain unfactored for many years to come. , the smallest 23 of the 54 listed numbers have been factored. While the RSA challenge officially ended in 2007, people are still attempting to find the factorizations. According to RSA Laboratories, "Now that the industry has a considerably more advanced understanding of the cryptanalytic strength of common symmetric-key and public-key algorithms, these challenges are no longer active." Some of the smaller prizes had been awarded at the time. The remaining prizes were retracted. The first RSA numbers generated, from RSA-100 to RSA-500, were labeled according to their number of decimal digits. Later, beginning with RSA-576, binary digits are counted instead. An exception to this is RSA-617, which was created before the change in the numbering scheme. The numbers are listed in increasing order below.

RSA-100

RSA-100 has 100 decimal digits (330 bits). Its factorization was announced on April 1, 1991, by Arjen K. Lenstra. Reportedly, the factorization took a few days using the multiple-polynomial quadratic sieve algorithm on a MasPar parallel computer. The value and factorization of RSA-100 are as follows: RSA-100 = 1522605027922533360535618378132637429718068114961380688657908494580122963258952897654000350692006139 RSA-100 = 37975227936943673922808872755445627854565536638199 × 40094690950920881030683735292761468389214899724061 It takes four hours to repeat this factorization using the progra
Msieve
on a 2200 MHz

Athlon 64 The Athlon 64 is a ninth-generation, AMD64-architecture microprocessor produced by Advanced Micro Devices (AMD), released on September 23, 2003. It is the third processor to bear the name ''Athlon'', and the immediate successor to the Athlon XP. T ...

processor. The number can be factorized in 72 minutes on overclocked to 3.5 GHz Intel Core2 Quad q9300, usin
GGNFS
an
Msieve
binaries running b
distributed version of the factmsieve Perl script

RSA-110

RSA-110 has 110 decimal digits (364 bits), and was factored in April 1992 by Arjen K. Lenstra and Mark S. Manasse in approximately one month. The number can be factorized in less than four hours on overclocked to 3.5 GHz Intel Core2 Quad q9300, usin
GGNFS
an
Msieve
binaries running b
distributed version of the factmsieve Perl script
The value and factorization are as follows: RSA-110 = 35794234179725868774991807832568455403003778024228226193532908190484670252364677411513516111204504060317568667 RSA-110 = 6122421090493547576937037317561418841225758554253106999 × 5846418214406154678836553182979162384198610505601062333

RSA-120

RSA-120 has 120 decimal digits (397 bits), and was factored in June 1993 by Thomas Denny, Bruce Dodson, Arjen K. Lenstra, and Mark S. Manasse. The computation took under three months of actual computer time. The value and factorization are as follows: RSA-120 = 227010481295437363334259960947493668895875336466084780038173258247009162675779735389791151574049166747880487470296548479 RSA-120 = 327414555693498015751146303749141488063642403240171463406883 × 693342667110830181197325401899700641361965863127336680673013

RSA-129

RSA-129, having 129 decimal digits (426 bits), was not part of the 1991 RSA Factoring Challenge, but rather related to

Martin Gardner Martin Gardner (October 21, 1914May 22, 2010) was an American popular mathematics and popular science writer with interests also encompassing scientific skepticism, micromagic, philosophy, religion, and literatureespecially the writings of Lew ...

Mathematical Games column Over a period of 24 years (January 1957 – December 1980), Martin Gardner wrote 288 consecutive monthly "Mathematical Games" columns for ''Scientific American'' magazine. During the next years, through June 1986, Gardner wrote 9 more columns, ...

in the August 1977 issue of ''

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it ...

''. RSA-129 was factored in April 1994 by a team led by

Derek Atkins Derek A Atkins is a computer scientist specializing in computer security. He studied electrical engineering and computer science at the Massachusetts Institute of Technology. In June 2014, he became the chief technology officer of SecureRF. A ...

Michael Graff Michael Graff is a co-author and one of several architects of BIND 9. In April 1994, he co-authored '' The Magic Words are Squeamish Ossifrage''. Graff graduated from Iowa State University with a degree in Computer Engineering. He is curren ...

, Arjen K. Lenstra and

Paul Leyland Paul Leyland is a British number theorist who has studied integer factorization and primality testing. He has contributed to the factorization of RSA-129, RSA-140, and RSA-155, as well as potential factorial primes as large as 400! + 1. He h ...

, using approximately 1600 computers from around 600 volunteers connected over the

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, p ...

. A US$100 token prize was awarded by RSA Security for the factorization, which was donated to the

Free Software Foundation The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985, to support the free software movement, with the organization's preference for software being distributed under copyleft ( ...

. The value and factorization are as follows: RSA-129 = 114381625757888867669235779976146612010218296721242362562561842935706935245733897830597123563958705058989075147599290026879543541 RSA-129 = 3490529510847650949147849619903898133417764638493387843990820577 × 32769132993266709549961988190834461413177642967992942539798288533 The factorization was found using the

Multiple Polynomial Quadratic Sieve The quadratic sieve algorithm (QS) is an integer factorization algorithm and, in practice, the second fastest method known (after the general number field sieve). It is still the fastest for integers under 100 decimal digits or so, and is considerab ...

algorithm. The factoring challenge included a message encrypted with RSA-129. When decrypted using the factorization the message was revealed to be "

The Magic Words are Squeamish Ossifrage "The Magic Words are Squeamish Ossifrage" was the solution to a challenge ciphertext posed by the inventors of the RSA cipher in 1977. The problem appeared in Martin Gardner's ''Mathematical Games column'' in the August 1977 issue of ''Scientific A ...

RSA-130

RSA-130 has 130 decimal digits (430 bits), and was factored on April 10, 1996, by a team led by Arjen K. Lenstra and composed of

Jim Cowie Jim or JIM may refer to: * Jim (given name), a given name * Jim, a diminutive form of the given name James * Jim, a short form of the given name Jimmy * OPCW-UN Joint Investigative Mechanism * ''Jim'' (comics), a series by Jim Woodring * ''Jim ...

, Marije Elkenbracht-Huizing, Wojtek Furmanski, Peter L. Montgomery,

Damian Weber Damian ( la, links=no, Damianus) may refer to: *Damian (given name) *Damian (surname) *Damian Subdistrict, in Longquanyi District, Chengdu, Sichuan, China See also *Damiani, an Italian surname *Damiano (disambiguation) *Damien (disambiguation) *Dam ...

and Joerg Zayer. The value and factorization are as follows: RSA-130 = 1807082088687404805951656164405905566278102516769401349170127021450056662540244048387341127590812303371781887966563182013214880557 RSA-130 = 39685999459597454290161126162883786067576449112810064832555157243 × 45534498646735972188403686897274408864356301263205069600999044599 The factorization was found using the

Number Field Sieve In number theory, the general number field sieve (GNFS) is the most efficient classical algorithm known for factoring integers larger than . Heuristically, its complexity for factoring an integer (consisting of bits) is of the form :\exp\left( ...

algorithm and the

polynomial In mathematics, a polynomial is an expression consisting of indeterminates (also called variables) and coefficients, that involves only the operations of addition, subtraction, multiplication, and positive-integer powers of variables. An exampl ...

5748302248738405200 x⁵ + 9882261917482286102 x⁴ - 13392499389128176685 x³ + 16875252458877684989 x² + 3759900174855208738 x¹ - 46769930553931905995 which has a root of 12574411168418005980468 modulo RSA-130.

RSA-140

RSA-140 has 140 decimal digits (463 bits), and was factored on February 2, 1999, by a team led by Herman te Riele and composed of Stefania Cavallar, Bruce Dodson, Arjen K. Lenstra, Paul Leyland,

Walter Lioen Walter may refer to: People * Walter (name), both a surname and a given name * Little Walter, American blues harmonica player Marion Walter Jacobs (1930–1968) * Gunther (wrestler), Austrian professional wrestler and trainer Walter Hahn (born 19 ...

, Peter L. Montgomery,

Brian Murphy Brian Murphy may refer to: Sportspeople * Brian Murphy (Jamaican cricketer) (born 1973), Jamaican cricketer * Brian Murphy (Zimbabwean cricketer) (born 1976), Zimbabwean cricketer * Brian Murphy (baseball) (born 1980), American head baseball coach ...

and Paul Zimmermann. The value and factorization are as follows: RSA-140 = 21290246318258757547497882016271517497806703963277216278233383215381949984056495911366573853021918316783107387995317230889569230873441936471 RSA-140 = 3398717423028438554530123627613875835633986495969597423490929302771479 × 6264200187401285096151654948264442219302037178623509019111660653946049 The factorization was found using the

algorithm and an estimated 2000 MIPS-years of computing time.

RSA-150

RSA-150 has 150 decimal digits (496 bits), and was withdrawn from the challenge by RSA Security. RSA-150 was eventually factored into two 75-digit primes by Aoki et al. in 2004 using the

general number field sieve In number theory, the general number field sieve (GNFS) is the most efficient classical algorithm known for factoring integers larger than . Heuristically, its complexity for factoring an integer (consisting of bits) is of the form :\exp\lef ...

(GNFS), years after bigger RSA numbers that were still part of the challenge had been solved. The value and factorization are as follows: RSA-150 = 155089812478348440509606754370011861770654545830995430655466945774312632703463465954363335027577729025391453996787414027003501631772186840890795964683 RSA-150 = 348009867102283695483970451047593424831012817350385456889559637548278410717 × 445647744903640741533241125787086176005442536297766153493419724532460296199

RSA-155

RSA-155 has 155 decimal digits (512 bits), and was factored on August 22, 1999, in a span of six months, by a team led by Herman te Riele and composed of Stefania Cavallar, Bruce Dodson, Arjen K. Lenstra, Walter Lioen, Peter L. Montgomery, Brian Murphy,

Karen Aardal Karen I. Aardal (born 1961) is a Norwegian and Dutch applied mathematician, theoretical computer scientist, and operations researcher. Her research involves combinatorial optimization, integer programming, approximation algorithms, and facility loc ...

, Jeff Gilchrist, Gerard Guillerm, Paul Leyland, Joel Marchand,

François Morain François () is a French masculine given name and surname, equivalent to the English name Francis. People with the given name * Francis I of France, King of France (), known as "the Father and Restorer of Letters" * Francis II of France, Ki ...

, Alec Muffett, Craig Putnam, Chris Putnam and Paul Zimmermann. The value and factorization are as follows: RSA-155 = 10941738641570527421809707322040357612003732945449205990913842131476349984288934784717997257891267332497625752899781833797076537244027146743531593354333897 RSA-155 = 1026395928297411057720541965739916759007165678080380668033419335217907113077 79 × 1066034883801684548209272203600128786792079585759892915222706082371930628086 43 The factorization was found using the

algorithm and an estimated 8000 MIPS-years of computing time.

RSA-160

RSA-160 has 160 decimal digits (530 bits), and was factored on April 1, 2003, by a team from the

University of Bonn The Rhenish Friedrich Wilhelm University of Bonn (german: Rheinische Friedrich-Wilhelms-Universität Bonn) is a public research university located in Bonn, North Rhine-Westphalia, Germany. It was founded in its present form as the ( en, Rhine ...

and the

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

Federal Office for Information Security The Federal Office for Information Security (german: Bundesamt für Sicherheit in der Informationstechnik, abbreviated as BSI) is the German upper-level federal agency in charge of managing computer and communication security for the German g ...

(BSI). The team contained J. Franke, F. Bahr, T. Kleinjung, M. Lochter, and M. Böhm. The value and factorization are as follows: RSA-160 = 2152741102718889701896015201312825429257773588845675980170497676778133145218859135673011059773491059602497907111585214302079314665202840140619946994927570407753 RSA-160 = 4542789285848139407168619064973883165613714577846979325095998470925000415733 5359 × 4738809060383201619663383230378895197326892292104095794474135464881202849390 9367 The factorization was found using the

algorithm.

RSA-170

RSA-170 has 170 decimal digits (563 bits) and was first factored on December 29, 2009, by D. Bonenberger and M. Krone from Fachhochschule Braunschweig/Wolfenbüttel. An independent factorization was completed by S. A. Danilov and I. A. Popovyan two days later. The value and factorization are as follows: RSA-170 = 26062623684139844921529879266674432197085925380486406416164785191859999628542069361450283931914514618683512198164805919882053057222974116478065095809832377336510711545759 RSA-170 = 3586420730428501486799804587268520423291459681059978161140231860633948450858 040593963 × 7267029064107019078863797763923946264136137803856996670313708936002281582249 587494493 The factorization was found using the

algorithm.

RSA-576

RSA-576 has 174 decimal digits (576 bits), and was factored on December 3, 2003, by J. Franke and T. Kleinjung from the University of Bonn. A cash prize of $10,000 was offered by RSA Security for a successful factorization. The value and factorization are as follows: RSA-576 = 188198812920607963838697239461650439807163563379417382700763356422988859715234665485319060606504743045317388011303396716199692321205734031879550656996221305168759307650257059 RSA-576 = 3980750864240649373971255005503864911990643623425267084063851895759463889572 61768583317 × 4727721461074353025362230719730482246329146953020971164598521711305207112563 63590397527 The factorization was found using the

algorithm.

RSA-180

RSA-180 has 180 decimal digits (596 bits), and was factored on May 8, 2010, by S. A. Danilov and I. A. Popovyan from

Moscow State University M. V. Lomonosov Moscow State University (MSU; russian: Московский государственный университет имени М. В. Ломоносова) is a public research university in Moscow, Russia and the most prestigious ...

, Russia. RSA-180 = 1911479277189866096892294666314546498129862462766673548641885036388072607034 3679905877620136513516127813425829612810920004670291298456875280033022177775 2773957404540495707851421041 RSA-180 = 4007800823297508779525813391041005725268293178158071765648821789984975727719 50624613470377 × 4769396887386118369955354773570708579399020760277882320319897758246062255957 73435668861833 The factorization was found using the

algorithm implementation running on three Intel Core i7 PCs.

RSA-190

RSA-190 has 190 decimal digits (629 bits), and was factored on November 8, 2010, by I. A. Popovyan from Moscow State University, Russia, and A. Timofeev from CWI, Netherlands. RSA-190 = 1907556405060696491061450432646028861081179759533184460647975622318915025587 1841757540549761551215932934922604641526300932385092466032074171247261215808 58185985938946945490481721756401423481 RSA-190 = 3171195257690152709485171289740475929805147316029450327784761927832793642798 1256542415724309619 × 6015260020444561641587641685526676183243543359471811072599763828083615704046 0481625355619404899

RSA-640

RSA-640 has 193 decimal digits (640 bits). A cash prize of US$20,000 was offered by RSA Security for a successful factorization. On November 2, 2005, F. Bahr, M. Boehm, J. Franke and T. Kleinjung of the German Federal Office for Information Security announced that they had factorized the number using GNFS as follows: RSA-640 = 3107418240490043721350750035888567930037346022842727545720161948823206440518 0815045563468296717232867824379162728380334154710731085019195485290073377248 22783525742386454014691736602477652346609 RSA-640 = 1634733645809253848443133883865090859841783670033092312181110852389333100104 508151212118167511579 × 1900871281664822113126851573935413975471896789968515493666638539088027103802 104498957191261465571 The computation took five months on 80 2.2 GHz AMD

Opteron Opteron is AMD's x86 former server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture (known generically as x86-64 or AMD64). It was released on April 22, 2003, with the ''Sledg ...

CPUs. The slightly larger RSA-200 was factored in May 2005 by the same team.

RSA-200

RSA-200 has 200 decimal digits (663 bits), and factors into the two 100-digit primes given below. On May 9, 2005, F. Bahr, M. Boehm, J. Franke, and T. Kleinjung announced Thorsten Kleinjung (2005-05-09)
We have factored RSA200 by GNFS
. Retrieved on 2008-03-10. that they had factorized the number using GNFS as follows: RSA-200 = 2799783391122132787082946763872260162107044678695542853756000992932612840010 7609345671052955360856061822351910951365788637105954482006576775098580557613 579098734950144178863178946295187237869221823983 RSA-200 = 3532461934402770121272604978198464368671197400197625023649303468776121253679 423200058547956528088349 × 7925869954478333033347085841480059687737975857364219960734330341455767872818 152135381409304740185467 The CPU time spent on finding these factors by a collection of parallel computers amounted – very approximately – to the equivalent of 75 years work for a single 2.2

GHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...

-based computer. Note that while this approximation serves to suggest the scale of the effort, it leaves out many complicating factors; the announcement states it more precisely.

RSA-210

RSA-210 has 210 decimal digits (696 bits) and was factored in September 2013 by Ryan Propper: RSA-210 = 2452466449002782119765176635730880184670267876783327597434144517150616008300 3858721695220839933207154910362682719167986407977672324300560059203563124656 1218465817904100131859299619933817012149335034875870551067 RSA-210 = 4359585683259407917999519653872144063854709102652201963187054821445240853452 75999740244625255428455944579 × 5625457617268841037562770073044474817438769440075105451049468510945483965774 79473472146228550799322939273

RSA-704

RSA-704 has 212 decimal digits (704 bits), and was factored by Shi Bai, Emmanuel Thomé and Paul Zimmermann. The factorization was announced July 2, 2012. A cash prize of US$30,000 was previously offered for a successful factorization. RSA-704 = 7403756347956171282804679609742957314259318888923128908493623263897276503402 8266276891996419625117843995894330502127585370118968098286733173273108930900 552505116877063299072396380786710086096962537934650563796359 RSA-704 = 9091213529597818878440658302600437485892608310328358720428512168960411528640 933367824950788367956756806141 × 8143859259110045265727809126284429335877899002167627883200914172429324360133 004116702003240828777970252499

RSA-220

RSA-220 has 220 decimal digits (729 bits), and was factored by S. Bai, P. Gaudry, A. Kruppa, E. Thomé and P. Zimmermann. The factorization was announced on May 13, 2016. RSA-220 = 2260138526203405784941654048610197513508038915719776718321197768109445641817 9666766085931213065825772506315628866769704480700018111497118630021124879281 99487482066070131066586646083327982803560379205391980139946496955261 RSA-220 = 6863656412267566274382371499288437800130842239979164844621244993321541061441 4642667938213644208420192054999687 × 3292907439486349812049301549212935291916455196536233952462686051169290349309 4652463337824866390738191765712603

RSA-230

RSA-230 has 230 decimal digits (762 bits), and was factored by Samuel S. Gross on August 15, 2018. RSA-230 = 1796949159794106673291612844957324615636756180801260007088891883553172646034 1490933493372247868650755230855864199929221814436684722874052065257937495694 3483892631711525225256544109808191706117425097024407180103648316382885188526 89 RSA-230 = 4528450358010492026612439739120166758911246047493700040073956759261590397250 033699357694507193523000343088601688589 × 3968132623150957588532394439049887341769533966621957829426966084093049516953 598120833228447171744337427374763106901

RSA-232

RSA-232 has 232 decimal digits (768 bits), and was factored on February 17, 2020, by N. L. Zamarashkin, D. A. Zheltkov and S. A. Matveev.INM RAS news
/ref> RSA-232 = 1009881397871923546909564894309468582818233821955573955141120516205831021338 5285453743661097571543636649133800849170651699217015247332943892702802343809 6090980497644054071120196541074755382494867277137407501157718230539834060616 2079 RSA-232 = 2966909333208360660361779924242630634742946262521852394401857157419437019472 3262390744910112571804274494074452751891 × 3403816175197563438006609498491521420547121760734723172735163413276050706174 8526506443144325148088881115083863017669

RSA-768

RSA-768 has 232 decimal digits (768 bits), and was factored on December 12, 2009, over the span of two years, by Thorsten Kleinjung, Kazumaro Aoki, Jens Franke, Arjen K. Lenstra, Emmanuel Thomé, Pierrick Gaudry, Alexander Kruppa, Peter Montgomery, Joppe W. Bos, Dag Arne Osvik, Herman te Riele, Andrey Timofeev, and Paul Zimmermann.Cryptology ePrint Archive: Report 2010/006
/ref> RSA-768 = 1230186684530117755130494958384962720772853569595334792197322452151726400507 2636575187452021997864693899564749427740638459251925573263034537315482685079 1702612214291346167042921431160222124047927473779408066535141959745985690214 3413 RSA-768 = 3347807169895689878604416984821269081770479498371376856891243138898288379387 8002287614711652531743087737814467999489 × 3674604366679959042824463379962795263227915816434308764267603228381573966651 1279233373417143396810270092798736308917 The CPU time spent on finding these factors by a collection of parallel computers amounted approximately to the equivalent of almost 2000 years of computing on a single-core 2.2 GHz AMD Opteron-based computer.

RSA-240

RSA-240 has 240 decimal digits (795 bits), and was factored in November 2019 by Fabrice Boudot, Pierrick Gaudry, Aurore Guillevic, Nadia Heninger, Emmanuel Thomé and Paul Zimmermann. RSA-240 = 1246203667817187840658350446081065904348203746516788057548187888832896668011 8821085503603957027250874750986476843845862105486553797025393057189121768431 8286362846948405301614416430468066875699415246993185704183030512549594371372 159029236099 RSA-240 = 5094359522858399145550510235808437141326483820241114731866602965218212064697 46700620316443478873837606252372049619334517 × 2446242088383181505678131390240028966538020925789314014520412213365584770951 78155258218897735030590669041302045908071447 The CPU time spent on finding these factors amounted to approximately 900 core-years on a 2.1 GHz Intel Xeon Gold 6130 CPU. Compared to the factorization of RSA-768, the authors estimate that better algorithms sped their calculations by a factor of 3–4 and faster computers sped their calculation by a factor of 1.25–1.67.

RSA-250

RSA-250 has 250 decimal digits (829 bits), and was factored in February 2020 by Fabrice Boudot, Pierrick Gaudry, Aurore Guillevic, Nadia Heninger, Emmanuel Thomé, and Paul Zimmermann. The announcement of the factorization occurred on February 28. RSA-250 = 2140324650240744961264423072839333563008614715144755017797754920881418023447 1401366433455190958046796109928518724709145876873962619215573630474547705208 0511905649310668769159001975940569345745223058932597669747168173806936489469 9871578494975937497937 RSA-250 = 6413528947707158027879019017057738908482501474294344720811685963202453234463 0238623598752668347708737661925585694639798853367 × 3337202759497815655622601060535511422794076034476755466678452098702384172921 0037080257448673296881877565718986258036932062711 The factorisation of RSA-250 utilised approximately 2700 CPU core-years, using a 2.1 GHz Intel Xeon Gold 6130 CPU as a reference. The computation was performed with the Number Field Sieve algorithm, using the open sourc
CADO-NFS software
The team dedicated the computation to Peter Montgomery, an American mathematician known for his contributions to

and

cryptography Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adv ...

who died on February 18, 2020.

RSA-260

RSA-260 has 260 decimal digits (862 bits), and has not been factored so far. RSA-260 = 2211282552952966643528108525502623092761208950247001539441374831912882294140 2001986512729726569746599085900330031400051170742204560859276357953757185954 2988389587092292384910067030341246205457845664136645406842143612930176940208 46391065875914794251435144458199

RSA-270

RSA-270 has 270 decimal digits (895 bits), and has not been factored so far. RSA-270 = 2331085303444075445276376569106805241456198124803054490429486119684959182451 3578286788836931857711641821391926857265831491306067262691135402760979316634 1626693946596196427744273886601876896313468704059066746903123910748277606548 649151920812699309766587514735456594993207

RSA-896

RSA-896 has 270 decimal digits (896 bits), and has not been factored so far. A cash prize of $75,000 was previously offered for a successful factorization. RSA-896 = 4120234369866595438555313653325759481798116998443279828454556264338764455652 4842619809887042316184187926142024718886949256093177637503342113098239748515 0944909106910269861031862704114880866970564902903653658867433731720813104105 190864254793282601391257624033946373269391

RSA-280

RSA-280 has 280 decimal digits (928 bits), and has not been factored so far. RSA-280 = 1790707753365795418841729699379193276395981524363782327873718589639655966058 5783742549640396449103593468573113599487089842785784500698716853446786525536 5503525160280656363736307175332772875499505341538927978510751699922197178159 7724733184279534477239566789173532366357270583106789

RSA-290

RSA-290 has 290 decimal digits (962 bits), and has not been factored so far. RSA-290 = 3050235186294003157769199519894966400298217959748768348671526618673316087694 3419156362946151249328917515864630224371171221716993844781534383325603218163 2549201100649908073932858897185243836002511996505765970769029474322210394327 60575157628357292075495937664206199565578681309135044121854119

RSA-300

RSA-300 has 300 decimal digits (995 bits), and has not been factored so far. RSA-300 = 2769315567803442139028689061647233092237608363983953254005036722809375824714 9473946190060218756255124317186573105075074546238828817121274630072161346956 4396741836389979086904304472476001839015983033451909174663464663867829125664 459895575157178816900228792711267471958357574416714366499722090015674047

RSA-309

RSA-309 has 309 decimal digits (1,024 bits), and has not been factored so far. RSA-309 = 1332943998825757583801437794588036586217112243226684602854588261917276276670 5425540467426933349195015527349334314071822840746357352800368666521274057591 1870128339157499072351179666739658503429931021985160714113146720277365006623 6927218079163559142755190653347914002967258537889160429597714204365647842739 10949

RSA-1024

RSA-1024 has 309 decimal digits (1,024 bits), and has not been factored so far. $100,000 was previously offered for factorization. RSA-1024 = 135066410865995223349603216278805969938881475605667027524485143851526510604 859533833940287150571909441798207282164471551373680419703964191743046496589 274256239341020864383202110372958725762358509643110564073501508187510676594 629205563685529475213500852879416377328533906109750544334999811150056977236 890927563

RSA-310

RSA-310 has 310 decimal digits (1,028 bits), and has not been factored so far. RSA-310 = 1848210397825850670380148517702559371400899745254512521925707445580334710601 4125276757082979328578439013881047668984294331264191394626965245834649837246 5163148188847336415136873623631778358751846501708714541673402642461569061162 0116380982484120857688483676576094865930188367141388795454378671343386258291 687641

RSA-320

RSA-320 has 320 decimal digits (1,061 bits), and has not been factored so far. RSA-320 = 2136810696410071796012087414500377295863767938372793352315068620363196552357 8837094085435000951700943373838321997220564166302488321590128061531285010636 8571638978998117122840139210685346167726847173232244364004850978371121744321 8270343654835754061017503137136489303437996367224915212044704472299799616089 2591129924218437

RSA-330

RSA-330 has 330 decimal digits (1,094 bits), and has not been factored so far. RSA-330 = 1218708633106058693138173980143325249157710686226055220408666600017481383238 1352456802425903555880722805261111079089882303717632638856140900933377863089 0634828167900405006112727432172179976427017137792606951424995281839383708354 6364684839261149319768449396541020909665209789862312609604983709923779304217 01862444655244698696759267

RSA-340

RSA-340 has 340 decimal digits (1,128 bits), and has not been factored so far. RSA-340 = 2690987062294695111996484658008361875931308730357496490239672429933215694995 2758588771223263308836649715112756731997946779608413232406934433532048898585 9176676580752231563884394807622076177586625973975236127522811136600110415063 0004691128152106812042872285697735145105026966830649540003659922618399694276 990464815739966698956947129133275233

RSA-350

RSA-350 has 350 decimal digits (1,161 bits), and has not been factored so far. RSA-350 = 2650719995173539473449812097373681101529786464211583162467454548229344585504 3495841191504413349124560193160478146528433707807716865391982823061751419151 6068496555750496764686447379170711424873128631468168019548127029171231892127 2886825928263239383444398948209649800021987837742009498347263667908976501360 3382322972552204068806061829535529820731640151

RSA-360

RSA-360 has 360 decimal digits (1,194 bits), and has not been factored so far. RSA-360 = 2186820202343172631466406372285792654649158564828384065217121866374227745448 7764963889680817334211643637752157994969516984539482486678141304751672197524 0052350576247238785129338002757406892629970748212734663781952170745916609168 9358372359962787832802257421757011302526265184263565623426823456522539874717 61591019113926725623095606566457918240614767013806590649

RSA-370

RSA-370 has 370 decimal digits (1,227 bits), and has not been factored so far. RSA-370 = 1888287707234383972842703127997127272470910519387718062380985523004987076701 7212819937261952549039800018961122586712624661442288502745681454363170484690 7379449525034797494321694352146271320296579623726631094822493455672541491544 2700993152879235272779266578292207161032746297546080025793864030543617862620 878802244305286292772467355603044265985905970622730682658082529621

RSA-380

RSA-380 has 380 decimal digits (1,261 bits), and has not been factored so far. RSA-380 = 3013500443120211600356586024101276992492167997795839203528363236610578565791 8270750937407901898070219843622821090980641477056850056514799336625349678549 2187941807116344787358312651772858878058620717489800725333606564197363165358 2237779263423501952646847579678711825720733732734169866406145425286581665755 6977260763553328252421574633011335112031733393397168350585519524478541747311

RSA-390

RSA-390 has 390 decimal digits (1,294 bits), and has not been factored so far. RSA-390 = 2680401941182388454501037079346656065366941749082852678729822424397709178250 4623002472848967604282562331676313645413672467684996118812899734451228212989 1630084759485063423604911639099585186833094019957687550377834977803400653628 6955344904367437281870253414058414063152368812498486005056223028285341898040 0795447435865033046248751475297412398697088084321037176392288312785544402209 1083492089

RSA-400

RSA-400 has 400 decimal digits (1,327 bits), and has not been factored so far. RSA-400 = 2014096878945207511726700485783442547915321782072704356103039129009966793396 1419850865094551022604032086955587930913903404388675137661234189428453016032 6191193056768564862615321256630010268346471747836597131398943140685464051631 7519403149294308737302321684840956395183222117468443578509847947119995373645 3607109795994713287610750434646825511120586422993705980787028106033008907158 74500584758146849481

RSA-410

RSA-410 has 410 decimal digits (1,360 bits), and has not been factored so far. RSA-410 = 1965360147993876141423945274178745707926269294439880746827971120992517421770 1079138139324539033381077755540830342989643633394137538983355218902490897764 4412968474332754608531823550599154905901691559098706892516477785203855688127 0635069372091564594333528156501293924133186705141485137856845741766150159437 6063244163040088180887087028771717321932252992567756075264441680858665410918 431223215368025334985424358839

RSA-420

RSA-420 has 420 decimal digits (1,393 bits), and has not been factored so far. RSA-420 = 2091366302476510731652556423163330737009653626605245054798522959941292730258 1898373570076188752609749648953525484925466394800509169219344906273145413634 2427186266197097846022969248579454916155633686388106962365337549155747268356 4666583846809964354191550136023170105917441056517493690125545320242581503730 3405952887826925813912683942756431114820292313193705352716165790132673270514 3817744164107601735413785886836578207979

RSA-430

RSA-430 has 430 decimal digits (1,427 bits), and has not been factored so far. RSA-430 = 3534635645620271361541209209607897224734887106182307093292005188843884213420 6950355315163258889704268733101305820000124678051064321160104990089741386777 2424190744453885127173046498565488221441242210687945185565975582458031351338 2070785777831859308900851761495284515874808406228585310317964648830289141496 3289966226854692560410075067278840383808716608668377947047236323168904650235 70092246473915442026549955865931709542468648109541

RSA-440

RSA-440 has 440 decimal digits (1,460 bits), and has not been factored so far. RSA-440 = 2601428211955602590070788487371320550539810804595235289423508589663391270837 4310252674800592426746319007978890065337573160541942868114065643853327229484 5029942332226171123926606357523257736893667452341192247905168387893684524818 0307729497304959710847337973805145673263119916483529703607405432752966630781 2234597766390750441445314408171802070904072739275930410299359006059619305590 701939627725296116299946059898442103959412221518213407370491

RSA-450

RSA-450 has 450 decimal digits (1,493 bits), and has not been factored so far. RSA-450 = 1984634237142836623497230721861131427789462869258862089878538009871598692569 0078791591684242367262529704652673686711493985446003494265587358393155378115 8032447061155145160770580926824366573211993981662614635734812647448360573856 3132247491715526997278115514905618953253443957435881503593414842367096046182 7643434794849824315251510662855699269624207451365738384255497823390996283918 3287667419172988072221996532403300258906083211160744508191024837057033

RSA-460

RSA-460 has 460 decimal digits (1,526 bits), and has not been factored so far. RSA-460 = 1786856020404004433262103789212844585886400086993882955081051578507634807524 1464078819812169681394445771476334608488687746254318292828603396149562623036 3564554675355258128655971003201417831521222464468666642766044146641933788836 8932452217321354860484353296131403821175862890998598653858373835628654351880 4806362231643082386848731052350115776715521149453708868428108303016983133390 0416365515466857004900847501644808076825638918266848964153626486460448430073 4909

RSA-1536

RSA-1536 has 463 decimal digits (1,536 bits), and has not been factored so far. $150,000 was previously offered for successful factorization. RSA-1536 = 184769970321174147430683562020016440301854933866341017147178577491065169671 116124985933768430543574458561606154457179405222971773252466096064694607124 962372044202226975675668737842756238950876467844093328515749657884341508847 552829818672645133986336493190808467199043187438128336350279547028265329780 293491615581188104984490831954500984839377522725705257859194499387007369575 568843693381277961308923039256969525326162082367649031603655137144791393234 7169566988069

RSA-470

RSA-470 has 470 decimal digits (1,559 bits), and has not been factored so far. RSA-470 = 1705147378468118520908159923888702802518325585214915968358891836980967539803 6897711442383602526314519192366612270595815510311970886116763177669964411814 0957486602388713064698304619191359016382379244440741228665455229545368837485 5874455212895044521809620818878887632439504936237680657994105330538621759598 4047709603954312447692725276887594590658792939924609261264788572032212334726 8553025718835659126454325220771380103576695555550710440908570895393205649635 76770285413369

RSA-480

RSA-480 has 480 decimal digits (1,593 bits), and has not been factored so far. RSA-480 = 3026570752950908697397302503155918035891122835769398583955296326343059761445 7144169659817040125185215913853345598217234371231338324773210726853524776378 4105186549246199888070331088462855743520880671299302895546822695492968577380 7067958428022008294111984222973260208233693152589211629901686973933487362360 8129660418514569063995282978176790149760521395548532814196534676974259747930 6858645849268328985687423881853632604706175564461719396117318298679820785491 875674946700413680932103

RSA-490

RSA-490 has 490 decimal digits (1,626 bits), and has not been factored so far. RSA-490 = 1860239127076846517198369354026076875269515930592839150201028353837031025971 3738522164743327949206433999068225531855072554606782138800841162866037393324 6578171804201717222449954030315293547871401362961501065002486552688663415745 9758925793594165651020789220067311416926076949777767604906107061937873540601 5942747316176193775374190713071154900658503269465516496828568654377183190586 9537640698044932638893492457914750855858980849190488385315076922453755527481 1376719096144119390052199027715691

RSA-500

RSA-500 has 500 decimal digits (1,659 bits) and has not been factored so far. RSA-500 = 1897194133748626656330534743317202527237183591953428303184581123062450458870 7687605943212347625766427494554764419515427586743205659317254669946604982419 7301601038125215285400688031516401611623963128370629793265939405081077581694 4786041721411024641038040278701109808664214800025560454687625137745393418221 5494821277335671735153472656328448001134940926442438440198910908603252678814 7850601132077287172819942445113232019492229554237898606631074891074722425617 39680319169243814676235712934292299974411361

RSA-617

RSA-617 has 617 decimal digits (2,048 bits) and has not been factored so far. RSA-617 = 2270180129378501419358040512020458674106123596276658390709402187921517148311 9139894870133091111044901683400949483846818299518041763507948922590774925466 0881718792594659210265970467004498198990968620394600177430944738110569912941 2854289188085536270740767072259373777266697344097736124333639730805176309150 6836310795312607239520365290032105848839507981452307299417185715796297454995 0235053160409198591937180233074148804462179228008317660409386563445710347785 5345712108053073639453592393265186603051504106096643731332367283153932350006 7937107541955437362433248361242525945868802353916766181532375855504886901432 221349733

RSA-2048

RSA-2048 has 617 decimal digits (2,048 bits). It is the largest of the RSA numbers and carried the largest cash prize for its factorization, $200,000. The RSA-2048 may not be factorizable for many years to come, unless considerable advances are made in

integer factorization In number theory, integer factorization is the decomposition of a composite number into a product of smaller integers. If these factors are further restricted to prime numbers, the process is called prime factorization. When the numbers are s ...

computational power Moore's law is the observation that the number of transistors in a dense integrated circuit (IC) doubles about every two years. Moore's law is an observation and projection of a historical trend. Rather than a law of physics, it is an empir ...

in the near future. RSA-2048 = 2519590847565789349402718324004839857142928212620403202777713783604366202070 7595556264018525880784406918290641249515082189298559149176184502808489120072 8449926873928072877767359714183472702618963750149718246911650776133798590957 0009733045974880842840179742910064245869181719511874612151517265463228221686 9987549182422433637259085141865462043576798423387184774447920739934236584823 8242811981638150106748104516603773060562016196762561338441436038339044149526 3443219011465754445417842402092461651572335077870774981712577246796292638635 6373289912154831438167899885040445364023527381951378636564391212010397122822 120720357

Notes

References

* RSA Factoring Challenge Administrator (1997-10-12)
RSA Challenge List
* RSA Laboratories
The RSA Challenge Numbers
(archived by the

Internet Archive The Internet Archive is an American digital library with the stated mission of "universal access to all knowledge". It provides free public access to collections of digitized materials, including websites, software applications/games, music, ...

in 2006 before the RSA challenge ended). * RSA Laboratories, * Kazumaro Aoki, Yuji Kida, Takeshi Shimoyama, Hiroki Ueda
GNFS Factoring Statistics of RSA-100, 110, ..., 150
Cryptology ePrint Archive, Report 2004/095, 2004.

External links

Steven Levy Steven Levy (born 1951) is an American journalist and Editor at Large for ''Wired'' who has written extensively for publications on computers, technology, cryptography, the internet, cybersecurity, and privacy. He is the author of the 1984 book ...

(March 1996)
Wisecrackers
in

Wired News ''Wired'' (stylized as ''WIRED'') is a monthly American magazine, published in print and online editions, that focuses on how emerging technologies affect culture, the economy, and politics. Owned by Condé Nast, it is headquartered in San Fran ...

. Has coverage on RSA-129. {{DEFAULTSORT:Rsa Numbers RSA Factoring Challenge Integer factorization algorithms Large integers