Knowledge (XXG)

Key size

Source đź“ť

550:, an expert in quantum computing: "The time needed to factor an RSA integer is the same order as the time needed to use that same integer as modulus for a single RSA encryption. In other words, it takes no more time to break RSA on a quantum computer (up to a multiplicative constant) than to use it legitimately on a classical computer." The general consensus is that these public key algorithms are insecure at any key size if sufficiently large quantum computers capable of running Shor's algorithm become available. The implication of this attack is that all data encrypted using current standards based security systems such as the ubiquitous 597:"A sufficiently large quantum computer, if built, would be capable of undermining all widely-deployed public key algorithms used for key establishment and digital signatures. It is generally accepted that quantum computing techniques are much less effective against symmetric algorithms than against current widely used public key algorithms. While public key cryptography requires changes in the fundamental design to protect against a potential future quantum computer, symmetric key algorithms are believed to be secure provided a sufficiently large key size is used. The public-key algorithms ( 617:, and NSA is not specifying any commercial quantum resistant standards at this time. NSA expects that NIST will play a leading role in the effort to develop a widely accepted, standardized set of quantum resistant algorithms. Given the level of interest in the cryptographic community, we hope that there will be quantum resistant algorithms widely available in the next decade. The AES-256 and SHA-384 algorithms are symmetric, and believed to be safe from attack by a large quantum computer." 1963: 625:"A cryptanalytically-relevant quantum computer (CRQC) would have the potential to break public-key systems (sometimes referred to as asymmetric cryptography) that are used today. Given foreign pursuits in quantum computing, now is the time to plan, prepare and budget for a transition to QR algorithms to assure sustained protection of NSS and related assets in the event a CRQC becomes an achievable reality." 233: 590:/2 bits of security. Quantum brute force is easily defeated by doubling the key length, which has little extra computational cost in ordinary use. This implies that at least a 256-bit symmetric key is required to achieve 128-bit security rating against a quantum computer. As mentioned above, the NSA announced in 2015 that it plans to transition to quantum-resistant algorithms. 116:
and so it is only the difficulty of obtaining the key that determines security of the system, provided that there is no analytic attack (i.e. a "structural weakness" in the algorithms or protocols used), and assuming that the key is not otherwise available (such as via theft, extortion, or compromise
80:
was designed to have a 168-bit key, but an attack of complexity 2 is now known (i.e. Triple DES now only has 112 bits of security, and of the 168 bits in the key the attack has rendered 56 'ineffective' towards security). Nevertheless, as long as the security (understood as "the amount of effort it
196:
The actual degree of security achieved over time varies, as more computational power and more powerful mathematical analytic methods become available. For this reason, cryptologists tend to look at indicators that an algorithm or key length shows signs of potential vulnerability, to move to longer
582:. Bennett, Bernstein, Brassard, and Vazirani proved in 1996 that a brute-force key search on a quantum computer cannot be faster than roughly 2 invocations of the underlying cryptographic algorithm, compared with roughly 2 in the classical case. Thus in the presence of large quantum computers an 218:
revealed additional dangers in using Diffie-Hellman key exchange when only one or a few common 1024-bit or smaller prime moduli are in use. This practice, somewhat common at the time, allows large amounts of communications to be compromised at the expense of attacking a small number of primes.
201:
using 400 computers over 11 months. The factored number was of a special form; the special number field sieve cannot be used on RSA keys. The computation is roughly equivalent to breaking a 700 bit RSA key. However, this might be an advance warning that 1024 bit RSA keys used in secure online
982:
Adrian, David; Bhargavan, Karthikeyan; Durumeric, Zakir; Gaudry, Pierrick; Green, Matthew; Halderman, J. Alex; Heninger, Nadia; Springall, Drew; Thomé, Emmanuel; Valenta, Luke; VanderSloot, Benjamin; Wustrow, Eric; Zanella-Béguelin, Santiago; Zimmermann, Paul (October 2015).
514:
previously recommended 256-bit ECC for protecting classified information up to the SECRET level, and 384-bit for TOP SECRET; In 2015 it announced plans to transition to quantum-resistant algorithms by 2024, and until then recommends 384-bit for all classified information.
210:
observed that "Last time, it took nine years for us to generalize from a special to a nonspecial, hard-to-factor number" and when asked whether 1024-bit RSA keys are dead, said: "The answer to that question is an unqualified yes."
558:
used to protect access to sensitive computing systems is at risk. Encrypted data protected using public-key algorithms can be archived and may be broken at a later time, commonly known as retroactive/retrospective decryption or
473:
1024-bit RSA keys are equivalent in strength to 80-bit symmetric keys, 2048-bit RSA keys to 112-bit symmetric keys, 3072-bit RSA keys to 128-bit symmetric keys, and 15360-bit RSA keys to 256-bit symmetric keys. In 2003,
613:) are all vulnerable to attack by a sufficiently large quantum computer. While a number of interesting quantum resistant public key algorithms have been proposed external to NSA, nothing has been standardized by 295:
of keys in what is known as a brute-force attack. Because longer symmetric keys require exponentially more work to brute force search, a sufficiently long symmetric key makes this line of attack impractical.
149:). In light of this, and the practical difficulty of managing such long keys, modern cryptographic practice has discarded the notion of perfect secrecy as a requirement for encryption, and instead focuses on 132:
A key should, therefore, be large enough that a brute-force attack (possible against any encryption algorithm) is infeasible – i.e. would take too long and/or would take too much memory to execute.
478:
claimed that 1024-bit keys were likely to become crackable sometime between 2006 and 2010, while 2048-bit keys are sufficient until 2030. As of 2020 the largest RSA key publicly known to be cracked is
69:. Ideally, the lower-bound on an algorithm's security is by design equal to the key length (that is, the algorithm's design does not detract from the degree of security inherent in the key length). 366:
However, by the late 90s, it became clear that DES could be cracked in a few days' time-frame with custom-built hardware such as could be purchased by a large corporation or government. The book
499:(ECC) is an alternative set of asymmetric algorithms that is equivalently secure with shorter keys, requiring only approximately twice the bits as the equivalent symmetric algorithm. A 256-bit 1386: 1491: 1943: 1773: 493:, which is related to the integer factorization problem on which RSA's strength is based. Thus, a 2048-bit Diffie-Hellman key has about the same strength as a 2048-bit RSA key. 370:(O'Reilly and Associates) tells of the successful ability in 1998 to break 56-bit DES by a brute-force attack mounted by a cyber civil rights group with limited resources; see 1252: 351:
and NIST argued was sufficient for non-governmental protection at the time. The NSA has major computing resources and a large budget; some cryptographers including
1293: 1216: 1165: 614: 409: 1626: 1361: 633:(now referred to as CNSA 1.0), originally launched in January 2016, to the Commercial National Security Algorithm Suite 2.0 (CNSA 2.0), both summarized below: 459:
must be longer for equivalent resistance to attack than symmetric algorithm keys. The most common methods are assumed to be weak against sufficiently powerful
319:
would be able to search the possible keys more efficiently. If a suitably sized quantum computer would reduce a 128-bit key down to 64-bit security, roughly a
1579: 858: 630: 389:
published in 2001 uses key sizes of 128, 192 or 256 bits. Many observers consider 128 bits sufficient for the foreseeable future for symmetric algorithms of
1558:
Blaze, Matt; Diffie, Whitfield; Rivest, Ronald L.; et al. "Minimal Key Lengths for Symmetric Ciphers to Provide Adequate Commercial Security". January, 1996
1313: 1177: 402: 81:
would take to gain access") is sufficient for a particular application, then it does not matter if key length and security coincide. This is important for
1228: 1463: 1331: 610: 291:
Even if a symmetric cipher is currently unbreakable by exploiting structural weaknesses in its algorithm, it may be possible to run through the entire
1415: 1394: 117:
of computer systems). The widely accepted notion that the security of the system should depend on the key alone has been explicitly formulated by
940: 1124: 65:(i.e. a logarithmic measure of the fastest known attack against an algorithm), because the security of all algorithms can be violated by 578:) are widely conjectured to offer greater security against known quantum computing attacks. They are widely thought most vulnerable to 489:
algorithm has roughly the same key strength as RSA for the same key sizes. The work factor for breaking Diffie-Hellman is based on the
500: 1619: 272: 993: 401:
has issued guidance that it plans to switch to quantum computing resistant algorithms and now requires 256-bit AES keys for data
185:). Because each of these has a different level of cryptographic complexity, it is usual to have different key sizes for the same 76:
are designed to have security equal to their key length. However, after design, a new attack might be discovered. For instance,
534:
Derivatives of Shor's algorithm are widely conjectured to be effective against all mainstream public-key algorithms including
359:
complained that this made the cipher so weak that NSA computers would be able to break a DES key in a day through brute force
1822: 1260: 254: 1034: 888:"Transitions: Recommendation for Transitioning the Use of Cryptographic Algorithms and Key Lengths, NIST SP-800-131A Rev 2" 1612: 1516: 567: 504: 424: 390: 386: 324: 162: 1938: 1893: 1706: 543: 496: 178: 170: 86: 1365: 455:. These problems are time-consuming to solve, but usually faster than trying all possible keys by brute force. Thus, 1817: 560: 490: 215: 198: 197:
key sizes or more difficult algorithms. For example, as of May 2007, a 1039-bit integer was factored with the
1561:
Arjen K. Lenstra, Eric R. Verheul: Selecting Cryptographic Key Sizes. J. Cryptology 14(4): 255-293 (2001) —
243: 1933: 1450: 1154: 250: 1282: 1923: 1913: 1768: 1527: 1495: 1470: 1419: 1205: 1128: 551: 511: 398: 348: 340: 320: 153:, under which the computational requirements of breaking an encrypted text must be infeasible for an attacker. 82: 1594: 887: 189:, depending upon the algorithm used. For example, the security available with a 1024-bit key using asymmetric 126: 307:
increases. The large number of operations (2) required to try all possible 128-bit keys is widely considered
1991: 1918: 1908: 1711: 1671: 1664: 1654: 1649: 448: 375: 145:', the key length must be at least as large as the message and only used once (this algorithm is called the 73: 1659: 150: 1423: 1339: 1966: 1812: 1758: 575: 452: 1517:"Announcing the Commercial National Security Algorithm Suite 2.0, U/OO/194427-22, PP-22-1338, Ver. 1.0" 579: 528: 451:
depends on the intractability (computational and theoretical) of certain mathematical problems such as
316: 100:
are used to control the operation of a cipher so that only the correct key can convert encrypted text (
419:
for key agreement is now disallowed." NIST approved symmetric encryption algorithms include three-key
1928: 1852: 507:
key. A message encrypted with an elliptic key algorithm using a 109-bit long key was broken in 2004.
363:. The NSA disputed this, claiming that brute-forcing DES would take them "something like 91 years". 161:
Encryption systems are often grouped into families. Common families include symmetric systems (e.g.
1691: 524: 292: 1797: 1781: 1728: 1492:"NSA Releases Future Quantum-Resistant (QR) Algorithm Requirements for National Security Systems" 1390: 1305: 1132: 1087: 598: 360: 286: 190: 138: 118: 97: 66: 47: 1106: 1857: 1847: 1718: 1079: 845: 428: 416: 344: 186: 113: 470:, an update to the widely accepted recommendation of a 1024-bit minimum since at least 2002. 412:
proposed phasing out 80-bit keys by 2015. At 2005, 80-bit keys were allowed only until 2010.
1792: 1297: 1220: 1169: 1067: 460: 394: 352: 336: 312: 1530:. September 2022. Table IV: CNSA 2.0 algorithms, p. 9.; Table V: CNSA 1.0 algorithms, p. 10 547: 535: 467: 371: 166: 142: 1206:"Recommendation for Key Management; Part 3: Application-Specific Key Management Guidance" 1153:
Barker, Elaine; Barker, William; Burr, William; Polk, William; Smid, Miles (2005-08-01).
984: 378:
keys for general use. Because of this, DES was replaced in most security applications by
193:
is considered approximately equal in security to an 80-bit key in a symmetric algorithm.
415:
Since 2015, NIST guidance says that "the use of keys that provide less than 112 bits of
17: 1867: 1787: 1748: 1696: 1681: 1075: 825: 602: 539: 486: 456: 356: 182: 134: 122: 62: 1562: 1985: 1948: 1903: 1862: 1842: 1738: 1701: 1676: 1309: 1083: 1010: 992:. 22nd ACM Conference on Computer and Communications Security (CCS '15). Denver, CO. 914: 311:
for conventional digital computing techniques for the foreseeable future. However, a
308: 207: 1445: 206:, since they may become breakable in the foreseeable future. Cryptography professor 1898: 1743: 1733: 1723: 1686: 1635: 1590: 1335: 1256: 1084:"Minimal key lengths for symmetric ciphers to provide adequate commercial security" 555: 475: 146: 51: 31: 1550: 374:. Even before that demonstration, 56 bits was considered insufficient length for 1877: 1301: 1224: 1042: 232: 203: 1837: 1807: 1802: 1763: 1071: 1063: 420: 379: 101: 77: 1173: 89:
comes the closest with an effective security of roughly half its key length.
1827: 174: 109: 105: 531:. Of the two, Shor's offers the greater risk to current security systems. 1872: 1832: 1585: 436: 1464:"Commercial National Security Algorithm Suite and Quantum Computing FAQ" 1253:"A Cost-Based Security Analysis of Symmetric and Asymmetric Key Lengths" 571: 479: 382:, which has 112 bits of security when using 168-bit keys (triple key). 257: in this section. Unsourced material may be challenged and removed. 1753: 55: 408:
In 2003, the U.S. National Institute for Standards and Technology,
303:
bits, there are 2 possible keys. This number grows very rapidly as
777:
Algorithm for computing a condensed representation of information
691:
Algorithm for computing a condensed representation of information
1387:"Certicom Announces Elliptic Curve Cryptography Challenge Winner" 713:
Asymmetric algorithm for digitally signing firmware and software
702:
Asymmetric algorithm for digitally signing firmware and software
503:(ECDH) key has approximately the same safety factor as a 128-bit 1109:, Cato Institute Briefing Paper no. 51, Arnold G. Reinhold, 1999 606: 1608: 986:
Imperfect Forward Secrecy: How Diffie-Hellman Fails in Practice
844:
See the discussion on the relationship between key lengths and
85:, because no such algorithm is known to satisfy this property; 629:
Since September 2022, the NSA has been transitioning from the
432: 226: 43: 1574: 466:
Since 2015, NIST recommends a minimum of 2048-bit keys for
339:
was selected in 1974 as the base for what would become the
1552:
Recommendation for Key Management — Part 1: general,
523:
The two best known quantum computing attacks are based on
1580:
Articles discussing the implications of quantum computing
1035:"DES Stanford-NBS-NSA meeting recording & transcript" 941:"Researchers: 307-digit key crack endangers 1024-bit RSA" 27:
Number of bits in a key used by a cryptographic algorithm
848:
attacks at the bottom of this page for more information.
108:. All commonly-used ciphers are based on publicly known 857:
See the complete tables and the transition timeline at
1774:
Cryptographically secure pseudorandom number generator
1443:
Bennett C.H., Bernstein E., Brassard G., Vazirani U.,
1283:"Recommendation for Key Management: Part 1 – General" 1155:"Recommendation for Key Management – Part 1: General" 964: 61:
Key length defines the upper-bound on an algorithm's
1600: 1119: 1117: 1115: 554:
used to protect e-commerce and Internet banking and
343:. Lucifer's key length was reduced from 128 bits to 1886: 1642: 1446:
The strengths and weaknesses of quantum computation
763:Elliptic Curve Digital Signature Algorithm (ECDSA) 593:In a 2016 Quantum Computing FAQ, the NSA affirmed: 519:
Effect of quantum computing attacks on key strength
1082:; Thompson, Eric; Wiener, Michael (January 1996). 881: 879: 877: 752:Elliptic Curve Diffie-Hellman (ECDH) Key Exchange 744:Symmetric block cipher for information protection 658:Symmetric block cipher for information protection 574:) and collision resistant hash functions (such as 1575:www.keylength.com: An online keylength calculator 705:All parameters approved. SHA256/192 recommended. 1199: 1197: 1011:"How secure is AES against brute force attacks?" 915:"Researcher: RSA 1024-bit Encryption not Enough" 397:become available. However, as of 2015, the U.S. 173:). They may be grouped according to the central 623: 595: 1416:"Commercial National Security Algorithm Suite" 1294:National Institute of Standards and Technology 1217:National Institute of Standards and Technology 1166:National Institute of Standards and Technology 886:Barker, Elaine; Roginsky, Allen (March 2019). 1620: 1107:Strong Cryptography The Global Tide of Change 327:supports key lengths of 256 bits and longer. 8: 1555:NIST Special Publication 800-57. March, 2007 859:Commercial National Security Algorithm Suite 810:Asymmetric algorithm for digital signatures 766:Asymmetric algorithm for digital signatures 680:Asymmetric algorithm for digital signatures 631:Commercial National Security Algorithm Suite 125:(in the 1940s); the statements are known as 965:"Weak Diffie-Hellman and the Logjam Attack" 799:Asymmetric algorithm for key establishment 788:Asymmetric algorithm for key establishment 755:Asymmetric algorithm for key establishment 669:Asymmetric algorithm for key establishment 621:In a 2022 press release, the NSA notified: 323:equivalent. This is one of the reasons why 1627: 1613: 1605: 1601: 1204:Barker, Elaine; Dang, Quynh (2015-01-22). 273:Learn how and when to remove this message 726: 640: 873: 837: 710:Xtended Merkle Signature Scheme (XMSS) 427:. Approvals for two-key Triple DES and 566:Mainstream symmetric ciphers (such as 7: 255:adding citations to reliable sources 741:Advanced Encryption Standard (AES) 655:Advanced Encryption Standard (AES) 1364:. Cado-nfs-discuss. Archived from 435:'s Skipjack algorithm used in its 141:showed that to achieve so-called ' 129:and Shannon's Maxim respectively. 25: 785:Diffie-Hellman (DH) Key Exchange 1962: 1961: 1319:from the original on 2020-05-09. 999:from the original on 2022-10-10. 699:Leighton-Micali Signature (LMS) 546:. According to Professor Gilles 443:Asymmetric algorithm key lengths 231: 1360:Zimmermann, Paul (2020-02-28). 1234:from the original on 2015-02-26 1183:from the original on 2016-12-13 331:Symmetric algorithm key lengths 242:needs additional citations for 165:) and asymmetric systems (e.g. 1823:Information-theoretic security 586:-bit key can provide at least 157:Key size and encryption system 1: 501:Elliptic-curve Diffie–Hellman 439:program employs 80-bit keys. 1422:. 2015-08-09. Archived from 1393:. 2004-04-27. Archived from 1330:Kaliski, Burt (2003-05-06). 1131:. 2009-01-15. Archived from 939:Cheng, Jacqui (2007-05-23). 774:Secure Hash Algorithm (SHA) 688:Secure Hash Algorithm (SHA) 431:were withdrawn in 2015; the 387:Advanced Encryption Standard 1939:Message authentication code 1894:Cryptographic hash function 1707:Cryptographic hash function 1302:10.6028/NIST.SP.800-57pt1r5 1281:Barker, Elaine (May 2020). 1225:10.6028/NIST.SP.800-57pt3r1 544:elliptic curve cryptography 497:Elliptic-curve cryptography 403:classified up to Top Secret 171:Elliptic-curve cryptography 87:elliptic curve cryptography 2008: 1818:Harvest now, decrypt later 1473:. 2016-01-01. pp. 6–8 1362:"Factorization of RSA-250" 1125:"NSA Suite B Cryptography" 561:harvest now, decrypt later 491:discrete logarithm problem 284: 199:special number field sieve 1957: 1934:Post-quantum cryptography 1604: 1451:SIAM Journal on Computing 813:Minimum 3072-bit modulus 802:Minimum 3072-bit modulus 791:Minimum 3072-bit modulus 83:asymmetric-key algorithms 1924:Quantum key distribution 1914:Authenticated encryption 1769:Random number generation 1528:National Security Agency 1496:National Security Agency 1471:National Security Agency 1453:26(5): 1510-1523 (1997). 1420:National Security Agency 1332:"TWIRL and RSA Key Size" 1290:NIST Special Publication 1213:NIST Special Publication 1174:10.6028/NIST.SP.800-57p1 1162:NIST Special Publication 1129:National Security Agency 716:All parameters approved 449:public key cryptosystems 399:National Security Agency 341:Data Encryption Standard 74:symmetric-key algorithms 42:refers to the number of 18:Key space (cryptography) 1919:Public-key cryptography 1909:Symmetric-key algorithm 1712:Key derivation function 1672:Cryptographic primitive 1665:Authentication protocol 1655:Outline of cryptography 1650:History of cryptography 1595:TWIRL and RSA key sizes 1660:Cryptographic protocol 627: 619: 151:computational security 1813:End-to-end encryption 1759:Cryptojacking malware 1586:cryptographic toolkit 453:integer factorization 447:The effectiveness of 299:With a key of length 127:Kerckhoffs' principle 54:algorithm (such as a 1929:Quantum cryptography 1853:Trusted timestamping 251:improve this article 1692:Cryptographic nonce 694:SHA-384 or SHA-512 677:CRYSTALS-Dilithium 376:symmetric algorithm 315:capable of running 202:commerce should be 121:(in the 1880s) and 67:brute-force attacks 1798:Subliminal channel 1782:Pseudorandom noise 1729:Key (cryptography) 1391:BlackBerry Limited 1168:. Table 4, p. 66. 1080:Shimomura, Tsutomu 1068:Diffie, Whitefield 580:Grover's algorithm 529:Grover's algorithm 361:parallel computing 317:Grover's algorithm 287:Brute-force attack 223:Brute-force attack 139:information theory 119:Auguste Kerckhoffs 1979: 1978: 1975: 1974: 1858:Key-based routing 1848:Trapdoor function 1719:Digital signature 1524:media.defense.gov 1072:Rivest, Ronald L. 846:quantum computing 817: 816: 720: 719: 485:The Finite Field 461:quantum computers 417:security strength 395:quantum computers 393:'s quality until 283: 282: 275: 187:level of security 16:(Redirected from 1999: 1965: 1964: 1793:Insecure channel 1629: 1622: 1615: 1606: 1602: 1539: 1538: 1536: 1535: 1521: 1513: 1507: 1506: 1504: 1503: 1488: 1482: 1481: 1479: 1478: 1468: 1460: 1454: 1441: 1435: 1434: 1432: 1431: 1412: 1406: 1405: 1403: 1402: 1383: 1377: 1376: 1374: 1373: 1357: 1351: 1350: 1348: 1347: 1338:. Archived from 1336:RSA Laboratories 1327: 1321: 1320: 1318: 1287: 1278: 1272: 1271: 1269: 1268: 1259:. Archived from 1257:RSA Laboratories 1249: 1243: 1242: 1240: 1239: 1233: 1210: 1201: 1192: 1191: 1189: 1188: 1182: 1159: 1150: 1144: 1143: 1141: 1140: 1121: 1110: 1104: 1098: 1097: 1095: 1094: 1060: 1054: 1053: 1051: 1050: 1041:. Archived from 1031: 1025: 1024: 1022: 1021: 1007: 1001: 1000: 998: 991: 979: 973: 972: 961: 955: 954: 952: 951: 936: 930: 929: 927: 926: 911: 905: 904: 902: 901: 895:Nvlpubs.nist.gov 892: 883: 862: 855: 849: 842: 727: 641: 525:Shor's algorithm 353:Whitfield Diffie 313:quantum computer 278: 271: 267: 264: 258: 235: 227: 21: 2007: 2006: 2002: 2001: 2000: 1998: 1997: 1996: 1982: 1981: 1980: 1971: 1953: 1882: 1638: 1633: 1571: 1547: 1545:Further reading 1542: 1533: 1531: 1519: 1515: 1514: 1510: 1501: 1499: 1490: 1489: 1485: 1476: 1474: 1466: 1462: 1461: 1457: 1442: 1438: 1429: 1427: 1414: 1413: 1409: 1400: 1398: 1385: 1384: 1380: 1371: 1369: 1359: 1358: 1354: 1345: 1343: 1329: 1328: 1324: 1316: 1285: 1280: 1279: 1275: 1266: 1264: 1251: 1250: 1246: 1237: 1235: 1231: 1208: 1203: 1202: 1195: 1186: 1184: 1180: 1157: 1152: 1151: 1147: 1138: 1136: 1123: 1122: 1113: 1105: 1101: 1092: 1090: 1076:Schneier, Bruce 1062: 1061: 1057: 1048: 1046: 1033: 1032: 1028: 1019: 1017: 1009: 1008: 1004: 996: 989: 981: 980: 976: 963: 962: 958: 949: 947: 938: 937: 933: 924: 922: 913: 912: 908: 899: 897: 890: 885: 884: 875: 871: 866: 865: 856: 852: 843: 839: 834: 822: 666:CRYSTALS-Kyber 521: 482:with 829 bits. 463:in the future. 457:asymmetric keys 445: 372:EFF DES cracker 333: 289: 279: 268: 262: 259: 248: 236: 225: 183:Feistel ciphers 159: 143:perfect secrecy 95: 28: 23: 22: 15: 12: 11: 5: 2005: 2003: 1995: 1994: 1992:Key management 1984: 1983: 1977: 1976: 1973: 1972: 1970: 1969: 1958: 1955: 1954: 1952: 1951: 1946: 1944:Random numbers 1941: 1936: 1931: 1926: 1921: 1916: 1911: 1906: 1901: 1896: 1890: 1888: 1884: 1883: 1881: 1880: 1875: 1870: 1868:Garlic routing 1865: 1860: 1855: 1850: 1845: 1840: 1835: 1830: 1825: 1820: 1815: 1810: 1805: 1800: 1795: 1790: 1788:Secure channel 1785: 1779: 1778: 1777: 1766: 1761: 1756: 1751: 1749:Key stretching 1746: 1741: 1736: 1731: 1726: 1721: 1716: 1715: 1714: 1709: 1699: 1697:Cryptovirology 1694: 1689: 1684: 1682:Cryptocurrency 1679: 1674: 1669: 1668: 1667: 1657: 1652: 1646: 1644: 1640: 1639: 1634: 1632: 1631: 1624: 1617: 1609: 1599: 1598: 1588: 1582: 1577: 1570: 1569:External links 1567: 1566: 1565: 1559: 1556: 1546: 1543: 1541: 1540: 1508: 1483: 1455: 1436: 1407: 1378: 1352: 1322: 1273: 1244: 1193: 1145: 1111: 1099: 1055: 1026: 1002: 974: 956: 931: 906: 872: 870: 867: 864: 863: 850: 836: 835: 833: 830: 829: 828: 826:Key stretching 821: 818: 815: 814: 811: 808: 804: 803: 800: 797: 793: 792: 789: 786: 782: 781: 778: 775: 771: 770: 767: 764: 760: 759: 756: 753: 749: 748: 745: 742: 738: 737: 734: 731: 718: 717: 714: 711: 707: 706: 703: 700: 696: 695: 692: 689: 685: 684: 681: 678: 674: 673: 670: 667: 663: 662: 659: 656: 652: 651: 648: 645: 603:Diffie-Hellman 540:Diffie-Hellman 520: 517: 487:Diffie-Hellman 444: 441: 357:Martin Hellman 337:Lucifer cipher 332: 329: 285:Main article: 281: 280: 239: 237: 230: 224: 221: 158: 155: 123:Claude Shannon 94: 91: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 2004: 1993: 1990: 1989: 1987: 1968: 1960: 1959: 1956: 1950: 1949:Steganography 1947: 1945: 1942: 1940: 1937: 1935: 1932: 1930: 1927: 1925: 1922: 1920: 1917: 1915: 1912: 1910: 1907: 1905: 1904:Stream cipher 1902: 1900: 1897: 1895: 1892: 1891: 1889: 1885: 1879: 1876: 1874: 1871: 1869: 1866: 1864: 1863:Onion routing 1861: 1859: 1856: 1854: 1851: 1849: 1846: 1844: 1843:Shared secret 1841: 1839: 1836: 1834: 1831: 1829: 1826: 1824: 1821: 1819: 1816: 1814: 1811: 1809: 1806: 1804: 1801: 1799: 1796: 1794: 1791: 1789: 1786: 1783: 1780: 1775: 1772: 1771: 1770: 1767: 1765: 1762: 1760: 1757: 1755: 1752: 1750: 1747: 1745: 1742: 1740: 1739:Key generator 1737: 1735: 1732: 1730: 1727: 1725: 1722: 1720: 1717: 1713: 1710: 1708: 1705: 1704: 1703: 1702:Hash function 1700: 1698: 1695: 1693: 1690: 1688: 1685: 1683: 1680: 1678: 1677:Cryptanalysis 1675: 1673: 1670: 1666: 1663: 1662: 1661: 1658: 1656: 1653: 1651: 1648: 1647: 1645: 1641: 1637: 1630: 1625: 1623: 1618: 1616: 1611: 1610: 1607: 1603: 1596: 1592: 1589: 1587: 1583: 1581: 1578: 1576: 1573: 1572: 1568: 1564: 1563:Citeseer link 1560: 1557: 1554: 1553: 1549: 1548: 1544: 1529: 1525: 1518: 1512: 1509: 1497: 1493: 1487: 1484: 1472: 1465: 1459: 1456: 1452: 1448: 1447: 1440: 1437: 1426:on 2022-02-18 1425: 1421: 1417: 1411: 1408: 1397:on 2016-09-27 1396: 1392: 1388: 1382: 1379: 1368:on 2020-02-28 1367: 1363: 1356: 1353: 1342:on 2017-04-17 1341: 1337: 1333: 1326: 1323: 1315: 1311: 1307: 1303: 1299: 1295: 1291: 1284: 1277: 1274: 1263:on 2017-01-13 1262: 1258: 1254: 1248: 1245: 1230: 1226: 1222: 1218: 1214: 1207: 1200: 1198: 1194: 1179: 1175: 1171: 1167: 1163: 1156: 1149: 1146: 1135:on 2009-02-07 1134: 1130: 1126: 1120: 1118: 1116: 1112: 1108: 1103: 1100: 1089: 1085: 1081: 1077: 1073: 1069: 1065: 1059: 1056: 1045:on 2012-05-03 1044: 1040: 1036: 1030: 1027: 1016: 1012: 1006: 1003: 995: 988: 987: 978: 975: 971:. 2015-05-20. 970: 966: 960: 957: 946: 942: 935: 932: 920: 916: 910: 907: 896: 889: 882: 880: 878: 874: 868: 860: 854: 851: 847: 841: 838: 831: 827: 824: 823: 819: 812: 809: 806: 805: 801: 798: 795: 794: 790: 787: 784: 783: 779: 776: 773: 772: 768: 765: 762: 761: 757: 754: 751: 750: 747:256-bit keys 746: 743: 740: 739: 735: 732: 729: 728: 725: 724: 715: 712: 709: 708: 704: 701: 698: 697: 693: 690: 687: 686: 682: 679: 676: 675: 671: 668: 665: 664: 661:256-bit keys 660: 657: 654: 653: 649: 646: 643: 642: 639: 638: 634: 632: 626: 622: 618: 616: 612: 608: 604: 600: 594: 591: 589: 585: 581: 577: 573: 569: 564: 562: 557: 553: 549: 545: 541: 537: 532: 530: 526: 518: 516: 513: 508: 506: 502: 498: 494: 492: 488: 483: 481: 477: 471: 469: 464: 462: 458: 454: 450: 442: 440: 438: 434: 430: 426: 422: 418: 413: 411: 406: 404: 400: 396: 392: 388: 383: 381: 377: 373: 369: 364: 362: 358: 354: 350: 346: 342: 338: 330: 328: 326: 322: 318: 314: 310: 306: 302: 297: 294: 288: 277: 274: 266: 256: 252: 246: 245: 240:This section 238: 234: 229: 228: 222: 220: 217: 216:Logjam attack 212: 209: 208:Arjen Lenstra 205: 200: 194: 192: 188: 184: 180: 176: 172: 168: 164: 156: 154: 152: 148: 144: 140: 136: 130: 128: 124: 120: 115: 111: 107: 103: 99: 92: 90: 88: 84: 79: 75: 70: 68: 64: 59: 57: 53: 52:cryptographic 49: 45: 41: 37: 33: 19: 1899:Block cipher 1744:Key schedule 1734:Key exchange 1724:Kleptography 1687:Cryptosystem 1636:Cryptography 1591:Burt Kaliski 1551: 1532:. Retrieved 1523: 1511: 1500:. Retrieved 1498:. 2022-09-07 1486: 1475:. Retrieved 1458: 1444: 1439: 1428:. Retrieved 1424:the original 1410: 1399:. Retrieved 1395:the original 1381: 1370:. Retrieved 1366:the original 1355: 1344:. Retrieved 1340:the original 1325: 1289: 1276: 1265:. Retrieved 1261:the original 1247: 1236:. Retrieved 1212: 1185:. Retrieved 1161: 1148: 1137:. Retrieved 1133:the original 1102: 1091:. Retrieved 1058: 1047:. Retrieved 1043:the original 1038: 1029: 1018:. Retrieved 1014: 1005: 985: 977: 968: 959: 948:. Retrieved 945:Ars Technica 944: 934: 923:. Retrieved 921:. 2007-05-23 918: 909: 898:. Retrieved 894: 853: 840: 769:Curve P-384 758:Curve P-384 722: 721: 636: 635: 628: 624: 620: 596: 592: 587: 583: 565: 533: 522: 509: 495: 484: 476:RSA Security 472: 465: 446: 414: 407: 384: 368:Cracking DES 367: 365: 347:, which the 334: 309:out of reach 304: 300: 298: 290: 269: 260: 249:Please help 244:verification 241: 213: 195: 160: 147:one-time pad 131: 96: 93:Significance 71: 60: 39: 35: 32:cryptography 29: 1887:Mathematics 1878:Mix network 1064:Blaze, Matt 736:Parameters 650:Parameters 263:August 2012 177:used (e.g. 114:open source 1838:Ciphertext 1808:Decryption 1803:Encryption 1764:Ransomware 1597:(May 2003) 1534:2024-04-14 1502:2024-04-14 1477:2024-04-21 1430:2020-07-12 1401:2016-09-24 1372:2020-07-12 1346:2017-11-24 1267:2016-09-24 1238:2017-11-24 1187:2019-01-08 1139:2016-09-24 1093:2011-10-14 1049:2016-09-24 1020:2016-09-24 969:weakdh.org 950:2016-09-24 925:2016-09-24 900:2023-02-11 869:References 730:Algorithm 644:Algorithm 421:Triple DES 380:Triple DES 204:deprecated 110:algorithms 102:ciphertext 78:Triple DES 50:used by a 40:key length 1828:Plaintext 1310:243189598 733:Function 647:Function 214:The 2015 175:algorithm 135:Shannon's 106:plaintext 1986:Category 1967:Category 1873:Kademlia 1833:Codetext 1776:(CSPRNG) 1314:Archived 1229:Archived 1178:Archived 1039:Toad.com 1015:EE Times 994:Archived 919:PC World 861:article. 820:See also 780:SHA-384 723:CNSA 1.0 683:Level V 672:Level V 637:CNSA 2.0 548:Brassard 437:Fortezza 429:Skipjack 137:work on 63:security 36:key size 1643:General 1088:Fortify 572:Twofish 480:RSA-250 345:56 bits 112:or are 1754:Keygen 1308:  1296:: 53. 1219:: 12. 609:, and 423:, and 335:IBM's 56:cipher 1784:(PRN) 1584:NIST 1520:(PDF) 1467:(PDF) 1317:(PDF) 1306:S2CID 1286:(PDF) 1232:(PDF) 1209:(PDF) 1181:(PDF) 1158:(PDF) 997:(PDF) 990:(PDF) 891:(PDF) 832:Notes 611:ECDSA 293:space 104:) to 72:Most 46:in a 807:RSA 796:RSA 615:NIST 607:ECDH 542:and 527:and 510:The 410:NIST 385:The 355:and 181:and 169:and 98:Keys 44:bits 1298:doi 1221:doi 1170:doi 599:RSA 576:SHA 570:or 568:AES 563:". 556:SSH 552:SSL 536:RSA 512:NSA 505:AES 468:RSA 433:NSA 425:AES 391:AES 349:NSA 325:AES 321:DES 253:by 191:RSA 179:ECC 167:RSA 163:AES 58:). 48:key 38:or 30:In 1988:: 1593:: 1526:. 1522:. 1494:. 1469:. 1449:. 1418:. 1389:. 1334:. 1312:. 1304:. 1292:. 1288:. 1255:. 1227:. 1215:. 1211:. 1196:^ 1176:. 1164:. 1160:. 1127:. 1114:^ 1086:. 1078:; 1074:; 1070:; 1066:; 1037:. 1013:. 967:. 943:. 917:. 893:. 876:^ 605:, 601:, 538:, 405:. 34:, 1628:e 1621:t 1614:v 1537:. 1505:. 1480:. 1433:. 1404:. 1375:. 1349:. 1300:: 1270:. 1241:. 1223:: 1190:. 1172:: 1142:. 1096:. 1052:. 1023:. 953:. 928:. 903:. 588:n 584:n 559:" 305:n 301:n 276:) 270:( 265:) 261:( 247:. 20:)

Index

Key space (cryptography)
cryptography
bits
key
cryptographic
cipher
security
brute-force attacks
symmetric-key algorithms
Triple DES
asymmetric-key algorithms
elliptic curve cryptography
Keys
ciphertext
plaintext
algorithms
open source
Auguste Kerckhoffs
Claude Shannon
Kerckhoffs' principle
Shannon's
information theory
perfect secrecy
one-time pad
computational security
AES
RSA
Elliptic-curve cryptography
algorithm
ECC

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

↑