Knowledge (XXG)

Hill cipher

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25: 82: 5127: 705: 1397: 972: 2813: 1190: 1633: 3280: 3123: 3431: 1929: 2961: 509: 1201: 776: 3489:. For example, an appropriately chosen matrix can guarantee that small differences before the matrix multiplication will result in large differences after the matrix multiplication. Indeed, some modern ciphers use a matrix multiplication step to provide diffusion. For example, the MixColumns step in 2326: 1421:
Thus, if we work modulo 26 as above, the determinant must be nonzero, and must not be divisible by 2 or 13. If the determinant is 0, or has common factors with the modular base, then the matrix cannot be used in the Hill cipher, and another matrix must be chosen (otherwise it will not be possible to
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plaintext/ciphertext character pairs can set up a linear system which can (usually) be easily solved; if it happens that this system is indeterminate, it is only necessary to add a few more plaintext/ciphertext pairs. Calculating this solution by standard linear algebra algorithms then takes very
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Unfortunately the gearing arrangements (and thus the key) were fixed for any given machine, so triple encryption was recommended for security: a secret nonlinear step, followed by the wide diffusive step from the machine, followed by a third secret nonlinear step. (The much later
2639: 2574: 1023: 1431: 3132: 2972: 4155: 442: 3291: 1789: 2821: 700:{\displaystyle {\begin{pmatrix}6&24&1\\13&16&10\\20&17&15\end{pmatrix}}{\begin{pmatrix}0\\2\\19\end{pmatrix}}={\begin{pmatrix}67\\222\\319\end{pmatrix}}\equiv {\begin{pmatrix}15\\14\\7\end{pmatrix}}{\pmod {26}}} 1392:{\displaystyle {\begin{pmatrix}8&5&10\\21&8&21\\21&12&8\end{pmatrix}}{\begin{pmatrix}15\\14\\7\end{pmatrix}}={\begin{pmatrix}260\\574\\539\end{pmatrix}}\equiv {\begin{pmatrix}0\\2\\19\end{pmatrix}}{\pmod {26}}} 967:{\displaystyle {\begin{pmatrix}6&24&1\\13&16&10\\20&17&15\end{pmatrix}}{\begin{pmatrix}2\\0\\19\end{pmatrix}}={\begin{pmatrix}31\\216\\325\end{pmatrix}}\equiv {\begin{pmatrix}5\\8\\13\end{pmatrix}}{\pmod {26}}} 2201: 2071: 1940: 3940: 2808:{\displaystyle K^{-1}\equiv 9^{-1}{\begin{pmatrix}5&23\\24&3\end{pmatrix}}\equiv 3{\begin{pmatrix}5&23\\24&3\end{pmatrix}}\equiv {\begin{pmatrix}15&17\\20&9\end{pmatrix}}{\pmod {26}}} 1778: 3804: 2440: 1185:{\displaystyle {\begin{pmatrix}6&24&1\\13&16&10\\20&17&15\end{pmatrix}}^{-1}{\pmod {26}}\equiv {\begin{pmatrix}8&5&10\\21&8&21\\21&12&8\end{pmatrix}}} 1628:{\displaystyle {\begin{vmatrix}6&24&1\\13&16&10\\20&17&15\end{vmatrix}}=6(16\cdot 15-10\cdot 17)-24(13\cdot 15-10\cdot 20)+1(13\cdot 17-16\cdot 20)=441\equiv 25{\pmod {26}}} 765: 498: 4212:, and in fact is weaker than either, and slightly more laborious to operate by pencil-and-paper. As the dimension increases, the cipher rapidly becomes infeasible for a human to operate by hand. 3275:{\displaystyle {\begin{pmatrix}15&17\\20&9\end{pmatrix}}{\begin{pmatrix}0\\19\end{pmatrix}}={\begin{pmatrix}323\\171\end{pmatrix}}\equiv {\begin{pmatrix}11\\15\end{pmatrix}}{\pmod {26}}} 3118:{\displaystyle {\begin{pmatrix}15&17\\20&9\end{pmatrix}}{\begin{pmatrix}7\\8\end{pmatrix}}={\begin{pmatrix}241\\212\end{pmatrix}}\equiv {\begin{pmatrix}7\\4\end{pmatrix}}{\pmod {26}},} 4160:
Additionally it seems to be prudent to avoid too many zeroes in the key matrix, since they reduce diffusion. The net effect is that the effective keyspace of a basic Hill cipher is about
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26). The cipher can, of course, be adapted to an alphabet with any number of letters; all arithmetic just needs to be done modulo the number of letters instead of modulo 26.
4194: 3951: 1701: 2629: 3556: 3426:{\displaystyle {\begin{pmatrix}7\\4\end{pmatrix}},{\begin{pmatrix}11\\15\end{pmatrix}}\to {\begin{pmatrix}H\\E\end{pmatrix}},{\begin{pmatrix}L\\P\end{pmatrix}}\to HELP} 1924:{\displaystyle HELP\to {\begin{pmatrix}H\\E\end{pmatrix}},{\begin{pmatrix}L\\P\end{pmatrix}}\to {\begin{pmatrix}7\\4\end{pmatrix}},{\begin{pmatrix}11\\15\end{pmatrix}}} 4364: 3647: 2956:{\displaystyle HIAT\to {\begin{pmatrix}H\\I\end{pmatrix}},{\begin{pmatrix}A\\T\end{pmatrix}}\to {\begin{pmatrix}7\\8\end{pmatrix}},{\begin{pmatrix}0\\19\end{pmatrix}}} 1669: 367: 4233:
also uses an unkeyed diffusive middle step). Such a combination was actually very powerful for 1929, and indicates that Hill apparently understood the concepts of a
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matrices. This is only an upper bound because not every matrix is invertible and thus usable as a key. The number of invertible matrices can be computed via the
4790: 2321:{\displaystyle {\begin{pmatrix}7\\8\end{pmatrix}},{\begin{pmatrix}0\\19\end{pmatrix}}\to {\begin{pmatrix}H\\I\end{pmatrix}},{\begin{pmatrix}A\\T\end{pmatrix}}} 4276: 2185:{\displaystyle {\begin{pmatrix}3&3\\2&5\end{pmatrix}}{\begin{pmatrix}11\\15\end{pmatrix}}\equiv {\begin{pmatrix}0\\19\end{pmatrix}}{\pmod {26}}} 1710:. Consequently, a useful variant of the Hill cipher adds 3 extra symbols (such as a space, a period and a question mark) to increase the modulus to 29. 2057:{\displaystyle {\begin{pmatrix}3&3\\2&5\end{pmatrix}}{\begin{pmatrix}7\\4\end{pmatrix}}\equiv {\begin{pmatrix}7\\8\end{pmatrix}}{\pmod {26}},} 4357: 46: 3822: 1724: 109:
in 1929, it was the first polygraphic cipher in which it was practical (though barely) to operate on more than three symbols at once.
4783: 3686: 68: 2569:{\displaystyle {\begin{pmatrix}a&b\\c&d\end{pmatrix}}^{-1}=(ad-bc)^{-1}{\begin{pmatrix}d&-b\\-c&a\end{pmatrix}}} 4350: 3661:. I.e., a matrix is invertible modulo 26 if and only if it is invertible both modulo 2 and modulo 13. The number of invertible 4986: 2579: 720: 453: 4776: 3490: 3481:
While matrix multiplication alone does not result in a secure cipher it is still a useful step when combined with other
5102: 5057: 4870: 4196:. For a 5 × 5 Hill cipher, that is about 114 bits. Of course, key search is not the most efficient known attack. 4328: 39: 33: 4225:) for this device, which performed a 6 × 6 matrix multiplication modulo 26 using a system of gears and chains. 5155: 4981: 5097: 4234: 3658: 50: 5087: 5077: 4932: 3510: 98: 4300: 4230: 1422:
decrypt). Fortunately, matrices which satisfy the conditions to be used in the Hill cipher are fairly common.
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The risk of the determinant having common factors with the modulus can be eliminated by making the modulus
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be the key and suppose the plaintext message is 'HELP'. Then this plaintext is represented by two pairs
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26. To decrypt the message, each block is multiplied by the inverse of the matrix used for encryption.
4150:{\displaystyle 26^{n^{2}}(1-1/2)(1-1/2^{2})\cdots (1-1/2^{n})(1-1/13)(1-1/13^{2})\cdots (1-1/13^{n}).} 5092: 5016: 4732: 4636: 4590: 4580: 4575: 4570: 4562: 3670: 324: 113: 4855: 4751: 4746: 4660: 4494: 4296: 4163: 1674: 977:
which corresponds to a ciphertext of 'FIN'. Every letter has changed. The Hill cipher has achieved
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is the set of all possible keys. The key space size is the number of possible keys. The effective
2586: 4961: 4945: 4892: 4727: 4646: 4552: 4484: 1014: 347: 335: 328: 125: 4415: 3527: 437:{\displaystyle {\begin{pmatrix}6&24&1\\13&16&10\\20&17&15\end{pmatrix}}} 5021: 5011: 4882: 4696: 4616: 4585: 4479: 4410: 3622: 2435: 1641: 1410: 314: 4215:
A Hill cipher of dimension 6 was implemented mechanically. Hill and a partner were awarded a
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The number of invertible matrices modulo 26 is the product of those two numbers. Hence it is
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26. Though this is not an essential feature of the cipher, this simple scheme is often used:
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is a combination of non-linear S-boxes with a carefully chosen matrix multiplication (MDS).
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In order to decrypt, we turn the ciphertext back into a vector, then simply multiply by the
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Jeffrey Overbey, William Traves, and Jerzy Wojdylo, On the Keyspace of the Hill Cipher,
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When operating on 2 symbols at once, a Hill cipher offers no particular advantage over
106: 102: 5149: 5112: 5067: 5026: 5006: 4902: 4865: 4840: 4688: 4542: 4522: 4502: 4453: 4433: 4259: 1703:, 25 has no common factors with 26, and this matrix can be used for the Hill cipher. 4282:
Lester S. Hill, Concerning Certain Linear Transformation Apparatus of Cryptography,
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as well as confusion and diffusion. Unfortunately, his machine did not sell.
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Equally, the number of invertible matrices modulo 13 (i.e. the order of GL(n,
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Since 'A' is 0, 'C' is 2 and 'T' is 19, the message is the vector:
4611: 4606: 4547: 3935:{\displaystyle 13^{n^{2}}(1-1/13)(1-1/13^{2})\cdots (1-1/13^{n}).} 80: 4245:
Other practical "pencil-and-paper" polygraphic ciphers include:
1773:{\displaystyle K={\begin{pmatrix}3&3\\2&5\end{pmatrix}}} 4772: 4346: 1017:
26, the inverse of the matrix used in the previous example is:
3799:{\displaystyle 2^{n^{2}}(1-1/2)(1-1/2^{2})\cdots (1-1/2^{n}).} 714:
of 'POH'. Now, suppose that our message is instead 'CAT', or:
338:, and it should be chosen randomly from the set of invertible 18: 4317:" implements the Hill cipher and shows the matrices involved 112:
The following discussion assumes an elementary knowledge of
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is an upper bound on the key size of the Hill cipher using
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One complications exist in picking the encrypting matrix:
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Taking the previous example ciphertext of 'POH', we get:
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This formula still holds after a modular reduction if a
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Lester S. Hill, Cryptography in an Algebraic Alphabet,
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Cryptographically secure pseudorandom number generator
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operations, because matrix multiplication can provide
3387: 3358: 3329: 3300: 3235: 3206: 3177: 3141: 3075: 3046: 3017: 2981: 2932: 2903: 2874: 2845: 2758: 2719: 2677: 2529: 2450: 2297: 2268: 2239: 2210: 2145: 2116: 2080: 2014: 1985: 1949: 1900: 1871: 1842: 1813: 1739: 1440: 1345: 1309: 1273: 1210: 1124: 1033: 920: 884: 848: 785: 760:{\displaystyle {\begin{pmatrix}2\\0\\19\end{pmatrix}}} 729: 653: 617: 581: 518: 493:{\displaystyle {\begin{pmatrix}0\\2\\19\end{pmatrix}}} 462: 376: 4166: 3954: 3825: 3689: 3625: 3572: 3530: 3456: 3294: 3135: 2975: 2824: 2642: 2589: 2443: 2371: 2341: 2204: 2074: 1943: 1792: 1727: 1677: 1644: 1434: 1413:. The matrix will have an inverse if and only if its 1204: 1026: 779: 723: 512: 456: 370: 353:
Consider the message 'ACT', and the key below (or GYB
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is inversible modulo n, where n is the modular base.
5050: 4806: 4715: 4687: 4659: 4599: 4561: 4493: 4467: 4424: 4391: 4380: 4188: 4149: 3934: 3798: 3641: 3611: 3550: 3469: 3425: 3274: 3117: 2955: 2807: 2623: 2568: 2422: 2357: 2320: 2184: 2056: 1923: 1772: 1695: 1663: 1627: 1391: 1184: 989:-dimensional Hill cipher can diffuse fully across 966: 759: 699: 492: 436: 85:Hill's cipher machine, from figure 4 of the patent 4275:Vol.36, June–July 1929, pp. 306–312. ( 3669:matrices modulo 2 is equal to the order of the 4295:, Vol.29, No.1, January 2005, pp59–72. ( 770:This time, the enciphered vector is given by: 4784: 4358: 334:The matrix used for encryption is the cipher 8: 1638:So, modulo 26, the determinant is 25. Since 16:Substitution cipher based on linear algebra 4791: 4777: 4769: 4388: 4365: 4351: 4343: 4339: 4335: 4331:" outlines the Hill Cipher with a Web page 1402:which gets us back to 'ACT', as expected. 4174: 4165: 4135: 4126: 4102: 4093: 4070: 4049: 4040: 4016: 4007: 3984: 3964: 3959: 3953: 3920: 3911: 3887: 3878: 3855: 3835: 3830: 3824: 3784: 3775: 3751: 3742: 3719: 3699: 3694: 3688: 3633: 3624: 3598: 3593: 3577: 3571: 3540: 3535: 3529: 3493:is a matrix multiplication. The function 3461: 3455: 3442:The basic Hill cipher is vulnerable to a 3382: 3353: 3324: 3295: 3293: 3256: 3230: 3201: 3172: 3136: 3134: 3096: 3070: 3041: 3012: 2976: 2974: 2927: 2898: 2869: 2840: 2823: 2789: 2753: 2714: 2672: 2663: 2647: 2641: 2612: 2588: 2524: 2515: 2481: 2445: 2442: 2414: 2395: 2379: 2370: 2346: 2340: 2292: 2263: 2234: 2205: 2203: 2166: 2140: 2111: 2075: 2073: 2035: 2009: 1980: 1944: 1942: 1895: 1866: 1837: 1808: 1791: 1734: 1726: 1676: 1655: 1643: 1609: 1435: 1433: 1373: 1340: 1304: 1268: 1205: 1203: 1119: 1100: 1091: 1028: 1025: 948: 915: 879: 843: 780: 778: 724: 722: 681: 648: 612: 576: 513: 511: 457: 455: 371: 369: 69:Learn how and when to remove this message 503:Thus the enciphered vector is given by: 130: 32:This article includes a list of general 124:Each letter is represented by a number 4286:Vol.38, 1931, pp. 135–154. 3612:{\displaystyle \log _{2}(26^{n^{2}})} 2423:{\displaystyle KK^{-1}=K^{-1}K=I_{2}} 7: 2195:and continue encryption as follows: 301:To encrypt a message, each block of 3264: 3104: 2797: 2174: 2043: 1617: 1381: 1108: 956: 689: 38:it lacks sufficient corresponding 14: 4284:The American Mathematical Monthly 4273:The American Mathematical Monthly 5126: 5125: 23: 3257: 3097: 2790: 2633:Hence in this case, we compute 2167: 2036: 1610: 1374: 1101: 1013:VMI in letters). We find that, 949: 682: 99:polygraphic substitution cipher 4987:Information-theoretic security 4141: 4114: 4108: 4081: 4078: 4058: 4055: 4028: 4022: 3995: 3992: 3972: 3926: 3899: 3893: 3866: 3863: 3843: 3790: 3763: 3757: 3730: 3727: 3707: 3606: 3586: 3408: 3350: 3268: 3258: 3108: 3098: 2895: 2837: 2801: 2791: 2609: 2590: 2580:modular multiplicative inverse 2512: 2493: 2260: 2178: 2168: 2047: 2037: 1863: 1805: 1621: 1611: 1594: 1570: 1561: 1537: 1528: 1504: 1385: 1375: 1112: 1102: 960: 950: 693: 683: 1: 4189:{\displaystyle 4.64n^{2}-1.7} 3450:. An opponent who intercepts 2434:can be computed by using the 1696:{\displaystyle 26=2\times 13} 3517:, in number of bits, is the 2624:{\displaystyle (ad-bc)^{-1}} 1425:For our example key matrix: 5103:Message authentication code 5058:Cryptographic hash function 4871:Cryptographic hash function 5172: 4982:Harvest now, decrypt later 3551:{\displaystyle 26^{n^{2}}} 305:letters (considered as an 5121: 5098:Post-quantum cryptography 4768: 4342: 4338: 4235:meet-in-the-middle attack 4200:Mechanical implementation 3659:Chinese Remainder Theorem 3446:because it is completely 1409:Not all matrices have an 5088:Quantum key distribution 5078:Authenticated encryption 4933:Random number generation 4329:Hill's Cipher Calculator 3642:{\displaystyle 4.7n^{2}} 1664:{\displaystyle 25=5^{2}} 5083:Public-key cryptography 5073:Symmetric-key algorithm 4876:Key derivation function 4836:Cryptographic primitive 4829:Authentication protocol 4819:Outline of cryptography 4814:History of cryptography 3521:of the key space size. 710:which corresponds to a 53:more precise citations. 4824:Cryptographic protocol 4374:Classical cryptography 4190: 4151: 3936: 3800: 3643: 3613: 3558:matrices of dimension 3552: 3471: 3444:known-plaintext attack 3427: 3276: 3119: 2957: 2809: 2625: 2570: 2424: 2359: 2358:{\displaystyle K^{-1}} 2322: 2186: 2058: 1925: 1774: 1697: 1665: 1629: 1393: 1186: 1005:of the key matrix (IFK 968: 761: 701: 494: 438: 313:) is multiplied by an 91:classical cryptography 86: 4977:End-to-end encryption 4923:Cryptojacking malware 4322:Hill Cipher Explained 4222:U.S. patent 1,845,947 4191: 4152: 3937: 3801: 3644: 3614: 3553: 3472: 3470:{\displaystyle n^{2}} 3428: 3277: 3120: 2958: 2810: 2626: 2571: 2425: 2360: 2335:is invertible, hence 2323: 2187: 2059: 1926: 1775: 1698: 1666: 1630: 1394: 1187: 969: 762: 702: 495: 439: 84: 5093:Quantum cryptography 5017:Trusted timestamping 4733:Index of coincidence 4637:Reservehandverfahren 4164: 3952: 3823: 3687: 3671:general linear group 3623: 3570: 3528: 3454: 3292: 3133: 2973: 2822: 2640: 2587: 2441: 2369: 2339: 2202: 2072: 1941: 1790: 1725: 1675: 1642: 1432: 1202: 1024: 777: 721: 510: 454: 368: 4856:Cryptographic nonce 4752:Kasiski examination 4747:Information leakage 4315:Hill Cipher Web App 4231:Even–Mansour cipher 2582:is used to compute 4962:Subliminal channel 4946:Pseudorandom noise 4893:Key (cryptography) 4728:Frequency analysis 4627:RasterschlĂĽssel 44 4186: 4147: 3932: 3796: 3639: 3609: 3548: 3467: 3423: 3402: 3373: 3344: 3315: 3272: 3250: 3221: 3192: 3166: 3115: 3090: 3061: 3032: 3006: 2953: 2947: 2918: 2889: 2860: 2805: 2783: 2744: 2702: 2621: 2566: 2560: 2475: 2420: 2355: 2318: 2312: 2283: 2254: 2225: 2182: 2160: 2131: 2105: 2054: 2029: 2000: 1974: 1921: 1915: 1886: 1857: 1828: 1770: 1764: 1693: 1661: 1625: 1492: 1389: 1367: 1331: 1295: 1262: 1182: 1176: 1085: 964: 942: 906: 870: 837: 757: 751: 697: 675: 639: 603: 570: 490: 484: 434: 428: 87: 5156:Classical ciphers 5143: 5142: 5139: 5138: 5022:Key-based routing 5012:Trapdoor function 4883:Digital signature 4764: 4763: 4760: 4759: 4655: 4654: 2430:. The inverse of 2365:exists such that 993:symbols at once. 361:URP in letters): 299: 298: 79: 78: 71: 5163: 5129: 5128: 4957:Insecure channel 4793: 4786: 4779: 4770: 4389: 4367: 4360: 4353: 4344: 4340: 4336: 4224: 4195: 4193: 4192: 4187: 4179: 4178: 4156: 4154: 4153: 4148: 4140: 4139: 4130: 4107: 4106: 4097: 4074: 4054: 4053: 4044: 4021: 4020: 4011: 3988: 3971: 3970: 3969: 3968: 3941: 3939: 3938: 3933: 3925: 3924: 3915: 3892: 3891: 3882: 3859: 3842: 3841: 3840: 3839: 3805: 3803: 3802: 3797: 3789: 3788: 3779: 3756: 3755: 3746: 3723: 3706: 3705: 3704: 3703: 3648: 3646: 3645: 3640: 3638: 3637: 3618: 3616: 3615: 3610: 3605: 3604: 3603: 3602: 3582: 3581: 3557: 3555: 3554: 3549: 3547: 3546: 3545: 3544: 3519:binary logarithm 3476: 3474: 3473: 3468: 3466: 3465: 3432: 3430: 3429: 3424: 3407: 3406: 3378: 3377: 3349: 3348: 3320: 3319: 3281: 3279: 3278: 3273: 3271: 3255: 3254: 3226: 3225: 3197: 3196: 3171: 3170: 3124: 3122: 3121: 3116: 3111: 3095: 3094: 3066: 3065: 3037: 3036: 3011: 3010: 2966:Then we compute 2962: 2960: 2959: 2954: 2952: 2951: 2923: 2922: 2894: 2893: 2865: 2864: 2814: 2812: 2811: 2806: 2804: 2788: 2787: 2749: 2748: 2707: 2706: 2671: 2670: 2655: 2654: 2632: 2630: 2628: 2627: 2622: 2620: 2619: 2575: 2573: 2572: 2567: 2565: 2564: 2523: 2522: 2489: 2488: 2480: 2479: 2429: 2427: 2426: 2421: 2419: 2418: 2403: 2402: 2387: 2386: 2364: 2362: 2361: 2356: 2354: 2353: 2327: 2325: 2324: 2319: 2317: 2316: 2288: 2287: 2259: 2258: 2230: 2229: 2191: 2189: 2188: 2183: 2181: 2165: 2164: 2136: 2135: 2110: 2109: 2063: 2061: 2060: 2055: 2050: 2034: 2033: 2005: 2004: 1979: 1978: 1934:Then we compute 1930: 1928: 1927: 1922: 1920: 1919: 1891: 1890: 1862: 1861: 1833: 1832: 1779: 1777: 1776: 1771: 1769: 1768: 1702: 1700: 1699: 1694: 1670: 1668: 1667: 1662: 1660: 1659: 1634: 1632: 1631: 1626: 1624: 1497: 1496: 1398: 1396: 1395: 1390: 1388: 1372: 1371: 1336: 1335: 1300: 1299: 1267: 1266: 1191: 1189: 1188: 1183: 1181: 1180: 1115: 1099: 1098: 1090: 1089: 1012: 1008: 973: 971: 970: 965: 963: 947: 946: 911: 910: 875: 874: 842: 841: 766: 764: 763: 758: 756: 755: 706: 704: 703: 698: 696: 680: 679: 644: 643: 608: 607: 575: 574: 499: 497: 496: 491: 489: 488: 443: 441: 440: 435: 433: 432: 360: 356: 131: 74: 67: 63: 60: 54: 49:this article by 40:inline citations 27: 26: 19: 5171: 5170: 5166: 5165: 5164: 5162: 5161: 5160: 5146: 5145: 5144: 5135: 5117: 5046: 4802: 4797: 4756: 4711: 4683: 4651: 4595: 4557: 4489: 4463: 4426:Polybius square 4420: 4384: 4376: 4371: 4310: 4268: 4250:Playfair cipher 4243: 4220: 4202: 4170: 4162: 4161: 4131: 4098: 4045: 4012: 3960: 3955: 3950: 3949: 3916: 3883: 3831: 3826: 3821: 3820: 3815: 3780: 3747: 3695: 3690: 3685: 3684: 3679: 3629: 3621: 3620: 3594: 3589: 3573: 3568: 3567: 3536: 3531: 3526: 3525: 3507: 3457: 3452: 3451: 3440: 3401: 3400: 3394: 3393: 3383: 3372: 3371: 3365: 3364: 3354: 3343: 3342: 3336: 3335: 3325: 3314: 3313: 3307: 3306: 3296: 3290: 3289: 3249: 3248: 3242: 3241: 3231: 3220: 3219: 3213: 3212: 3202: 3191: 3190: 3184: 3183: 3173: 3165: 3164: 3159: 3153: 3152: 3147: 3137: 3131: 3130: 3089: 3088: 3082: 3081: 3071: 3060: 3059: 3053: 3052: 3042: 3031: 3030: 3024: 3023: 3013: 3005: 3004: 2999: 2993: 2992: 2987: 2977: 2971: 2970: 2946: 2945: 2939: 2938: 2928: 2917: 2916: 2910: 2909: 2899: 2888: 2887: 2881: 2880: 2870: 2859: 2858: 2852: 2851: 2841: 2820: 2819: 2782: 2781: 2776: 2770: 2769: 2764: 2754: 2743: 2742: 2737: 2731: 2730: 2725: 2715: 2701: 2700: 2695: 2689: 2688: 2683: 2673: 2659: 2643: 2638: 2637: 2608: 2585: 2584: 2583: 2559: 2558: 2553: 2544: 2543: 2535: 2525: 2511: 2474: 2473: 2468: 2462: 2461: 2456: 2446: 2444: 2439: 2438: 2410: 2391: 2375: 2367: 2366: 2342: 2337: 2336: 2311: 2310: 2304: 2303: 2293: 2282: 2281: 2275: 2274: 2264: 2253: 2252: 2246: 2245: 2235: 2224: 2223: 2217: 2216: 2206: 2200: 2199: 2159: 2158: 2152: 2151: 2141: 2130: 2129: 2123: 2122: 2112: 2104: 2103: 2098: 2092: 2091: 2086: 2076: 2070: 2069: 2028: 2027: 2021: 2020: 2010: 1999: 1998: 1992: 1991: 1981: 1973: 1972: 1967: 1961: 1960: 1955: 1945: 1939: 1938: 1914: 1913: 1907: 1906: 1896: 1885: 1884: 1878: 1877: 1867: 1856: 1855: 1849: 1848: 1838: 1827: 1826: 1820: 1819: 1809: 1788: 1787: 1763: 1762: 1757: 1751: 1750: 1745: 1735: 1723: 1722: 1716: 1673: 1672: 1651: 1640: 1639: 1491: 1490: 1485: 1480: 1474: 1473: 1468: 1463: 1457: 1456: 1451: 1446: 1436: 1430: 1429: 1366: 1365: 1359: 1358: 1352: 1351: 1341: 1330: 1329: 1323: 1322: 1316: 1315: 1305: 1294: 1293: 1287: 1286: 1280: 1279: 1269: 1261: 1260: 1255: 1250: 1244: 1243: 1238: 1233: 1227: 1226: 1221: 1216: 1206: 1200: 1199: 1175: 1174: 1169: 1164: 1158: 1157: 1152: 1147: 1141: 1140: 1135: 1130: 1120: 1084: 1083: 1078: 1073: 1067: 1066: 1061: 1056: 1050: 1049: 1044: 1039: 1029: 1027: 1022: 1021: 1010: 1006: 999: 941: 940: 934: 933: 927: 926: 916: 905: 904: 898: 897: 891: 890: 880: 869: 868: 862: 861: 855: 854: 844: 836: 835: 830: 825: 819: 818: 813: 808: 802: 801: 796: 791: 781: 775: 774: 750: 749: 743: 742: 736: 735: 725: 719: 718: 674: 673: 667: 666: 660: 659: 649: 638: 637: 631: 630: 624: 623: 613: 602: 601: 595: 594: 588: 587: 577: 569: 568: 563: 558: 552: 551: 546: 541: 535: 534: 529: 524: 514: 508: 507: 483: 482: 476: 475: 469: 468: 458: 452: 451: 427: 426: 421: 416: 410: 409: 404: 399: 393: 392: 387: 382: 372: 366: 365: 358: 354: 122: 75: 64: 58: 55: 45:Please help to 44: 28: 24: 17: 12: 11: 5: 5169: 5167: 5159: 5158: 5148: 5147: 5141: 5140: 5137: 5136: 5134: 5133: 5122: 5119: 5118: 5116: 5115: 5110: 5108:Random numbers 5105: 5100: 5095: 5090: 5085: 5080: 5075: 5070: 5065: 5060: 5054: 5052: 5048: 5047: 5045: 5044: 5039: 5034: 5032:Garlic routing 5029: 5024: 5019: 5014: 5009: 5004: 4999: 4994: 4989: 4984: 4979: 4974: 4969: 4964: 4959: 4954: 4952:Secure channel 4949: 4943: 4942: 4941: 4930: 4925: 4920: 4915: 4913:Key stretching 4910: 4905: 4900: 4895: 4890: 4885: 4880: 4879: 4878: 4873: 4863: 4861:Cryptovirology 4858: 4853: 4848: 4846:Cryptocurrency 4843: 4838: 4833: 4832: 4831: 4821: 4816: 4810: 4808: 4804: 4803: 4798: 4796: 4795: 4788: 4781: 4773: 4766: 4765: 4762: 4761: 4758: 4757: 4755: 4754: 4749: 4744: 4730: 4725: 4719: 4717: 4713: 4712: 4710: 4709: 4704: 4699: 4693: 4691: 4685: 4684: 4682: 4681: 4676: 4671: 4665: 4663: 4657: 4656: 4653: 4652: 4650: 4649: 4644: 4639: 4634: 4632:Reihenschieber 4629: 4624: 4619: 4614: 4609: 4603: 4601: 4597: 4596: 4594: 4593: 4588: 4583: 4578: 4573: 4567: 4565: 4559: 4558: 4556: 4555: 4550: 4545: 4540: 4535: 4530: 4525: 4520: 4515: 4510: 4505: 4499: 4497: 4491: 4490: 4488: 4487: 4482: 4477: 4471: 4469: 4465: 4464: 4462: 4461: 4456: 4451: 4446: 4441: 4436: 4430: 4428: 4422: 4421: 4419: 4418: 4413: 4408: 4403: 4397: 4395: 4393:Polyalphabetic 4386: 4378: 4377: 4372: 4370: 4369: 4362: 4355: 4347: 4333: 4332: 4325: 4318: 4309: 4308:External links 4306: 4305: 4304: 4287: 4280: 4267: 4264: 4263: 4262: 4257: 4252: 4242: 4239: 4201: 4198: 4185: 4182: 4177: 4173: 4169: 4158: 4157: 4146: 4143: 4138: 4134: 4129: 4125: 4122: 4119: 4116: 4113: 4110: 4105: 4101: 4096: 4092: 4089: 4086: 4083: 4080: 4077: 4073: 4069: 4066: 4063: 4060: 4057: 4052: 4048: 4043: 4039: 4036: 4033: 4030: 4027: 4024: 4019: 4015: 4010: 4006: 4003: 4000: 3997: 3994: 3991: 3987: 3983: 3980: 3977: 3974: 3967: 3963: 3958: 3943: 3942: 3931: 3928: 3923: 3919: 3914: 3910: 3907: 3904: 3901: 3898: 3895: 3890: 3886: 3881: 3877: 3874: 3871: 3868: 3865: 3862: 3858: 3854: 3851: 3848: 3845: 3838: 3834: 3829: 3813: 3807: 3806: 3795: 3792: 3787: 3783: 3778: 3774: 3771: 3768: 3765: 3762: 3759: 3754: 3750: 3745: 3741: 3738: 3735: 3732: 3729: 3726: 3722: 3718: 3715: 3712: 3709: 3702: 3698: 3693: 3677: 3636: 3632: 3628: 3608: 3601: 3597: 3592: 3588: 3585: 3580: 3576: 3543: 3539: 3534: 3506: 3505:Key space size 3503: 3464: 3460: 3439: 3436: 3435: 3434: 3422: 3419: 3416: 3413: 3410: 3405: 3399: 3396: 3395: 3392: 3389: 3388: 3386: 3381: 3376: 3370: 3367: 3366: 3363: 3360: 3359: 3357: 3352: 3347: 3341: 3338: 3337: 3334: 3331: 3330: 3328: 3323: 3318: 3312: 3309: 3308: 3305: 3302: 3301: 3299: 3283: 3282: 3270: 3267: 3263: 3260: 3253: 3247: 3244: 3243: 3240: 3237: 3236: 3234: 3229: 3224: 3218: 3215: 3214: 3211: 3208: 3207: 3205: 3200: 3195: 3189: 3186: 3185: 3182: 3179: 3178: 3176: 3169: 3163: 3160: 3158: 3155: 3154: 3151: 3148: 3146: 3143: 3142: 3140: 3127: 3126: 3114: 3110: 3107: 3103: 3100: 3093: 3087: 3084: 3083: 3080: 3077: 3076: 3074: 3069: 3064: 3058: 3055: 3054: 3051: 3048: 3047: 3045: 3040: 3035: 3029: 3026: 3025: 3022: 3019: 3018: 3016: 3009: 3003: 3000: 2998: 2995: 2994: 2991: 2988: 2986: 2983: 2982: 2980: 2964: 2963: 2950: 2944: 2941: 2940: 2937: 2934: 2933: 2931: 2926: 2921: 2915: 2912: 2911: 2908: 2905: 2904: 2902: 2897: 2892: 2886: 2883: 2882: 2879: 2876: 2875: 2873: 2868: 2863: 2857: 2854: 2853: 2850: 2847: 2846: 2844: 2839: 2836: 2833: 2830: 2827: 2816: 2815: 2803: 2800: 2796: 2793: 2786: 2780: 2777: 2775: 2772: 2771: 2768: 2765: 2763: 2760: 2759: 2757: 2752: 2747: 2741: 2738: 2736: 2733: 2732: 2729: 2726: 2724: 2721: 2720: 2718: 2713: 2710: 2705: 2699: 2696: 2694: 2691: 2690: 2687: 2684: 2682: 2679: 2678: 2676: 2669: 2666: 2662: 2658: 2653: 2650: 2646: 2618: 2615: 2611: 2607: 2604: 2601: 2598: 2595: 2592: 2563: 2557: 2554: 2552: 2549: 2546: 2545: 2542: 2539: 2536: 2534: 2531: 2530: 2528: 2521: 2518: 2514: 2510: 2507: 2504: 2501: 2498: 2495: 2492: 2487: 2484: 2478: 2472: 2469: 2467: 2464: 2463: 2460: 2457: 2455: 2452: 2451: 2449: 2417: 2413: 2409: 2406: 2401: 2398: 2394: 2390: 2385: 2382: 2378: 2374: 2352: 2349: 2345: 2329: 2328: 2315: 2309: 2306: 2305: 2302: 2299: 2298: 2296: 2291: 2286: 2280: 2277: 2276: 2273: 2270: 2269: 2267: 2262: 2257: 2251: 2248: 2247: 2244: 2241: 2240: 2238: 2233: 2228: 2222: 2219: 2218: 2215: 2212: 2211: 2209: 2193: 2192: 2180: 2177: 2173: 2170: 2163: 2157: 2154: 2153: 2150: 2147: 2146: 2144: 2139: 2134: 2128: 2125: 2124: 2121: 2118: 2117: 2115: 2108: 2102: 2099: 2097: 2094: 2093: 2090: 2087: 2085: 2082: 2081: 2079: 2066: 2065: 2053: 2049: 2046: 2042: 2039: 2032: 2026: 2023: 2022: 2019: 2016: 2015: 2013: 2008: 2003: 1997: 1994: 1993: 1990: 1987: 1986: 1984: 1977: 1971: 1968: 1966: 1963: 1962: 1959: 1956: 1954: 1951: 1950: 1948: 1932: 1931: 1918: 1912: 1909: 1908: 1905: 1902: 1901: 1899: 1894: 1889: 1883: 1880: 1879: 1876: 1873: 1872: 1870: 1865: 1860: 1854: 1851: 1850: 1847: 1844: 1843: 1841: 1836: 1831: 1825: 1822: 1821: 1818: 1815: 1814: 1812: 1807: 1804: 1801: 1798: 1795: 1781: 1780: 1767: 1761: 1758: 1756: 1753: 1752: 1749: 1746: 1744: 1741: 1740: 1738: 1733: 1730: 1715: 1712: 1692: 1689: 1686: 1683: 1680: 1658: 1654: 1650: 1647: 1636: 1635: 1623: 1620: 1616: 1613: 1608: 1605: 1602: 1599: 1596: 1593: 1590: 1587: 1584: 1581: 1578: 1575: 1572: 1569: 1566: 1563: 1560: 1557: 1554: 1551: 1548: 1545: 1542: 1539: 1536: 1533: 1530: 1527: 1524: 1521: 1518: 1515: 1512: 1509: 1506: 1503: 1500: 1495: 1489: 1486: 1484: 1481: 1479: 1476: 1475: 1472: 1469: 1467: 1464: 1462: 1459: 1458: 1455: 1452: 1450: 1447: 1445: 1442: 1441: 1439: 1419: 1418: 1400: 1399: 1387: 1384: 1380: 1377: 1370: 1364: 1361: 1360: 1357: 1354: 1353: 1350: 1347: 1346: 1344: 1339: 1334: 1328: 1325: 1324: 1321: 1318: 1317: 1314: 1311: 1310: 1308: 1303: 1298: 1292: 1289: 1288: 1285: 1282: 1281: 1278: 1275: 1274: 1272: 1265: 1259: 1256: 1254: 1251: 1249: 1246: 1245: 1242: 1239: 1237: 1234: 1232: 1229: 1228: 1225: 1222: 1220: 1217: 1215: 1212: 1211: 1209: 1193: 1192: 1179: 1173: 1170: 1168: 1165: 1163: 1160: 1159: 1156: 1153: 1151: 1148: 1146: 1143: 1142: 1139: 1136: 1134: 1131: 1129: 1126: 1125: 1123: 1118: 1114: 1111: 1107: 1104: 1097: 1094: 1088: 1082: 1079: 1077: 1074: 1072: 1069: 1068: 1065: 1062: 1060: 1057: 1055: 1052: 1051: 1048: 1045: 1043: 1040: 1038: 1035: 1034: 1032: 1003:inverse matrix 998: 995: 975: 974: 962: 959: 955: 952: 945: 939: 936: 935: 932: 929: 928: 925: 922: 921: 919: 914: 909: 903: 900: 899: 896: 893: 892: 889: 886: 885: 883: 878: 873: 867: 864: 863: 860: 857: 856: 853: 850: 849: 847: 840: 834: 831: 829: 826: 824: 821: 820: 817: 814: 812: 809: 807: 804: 803: 800: 797: 795: 792: 790: 787: 786: 784: 768: 767: 754: 748: 745: 744: 741: 738: 737: 734: 731: 730: 728: 708: 707: 695: 692: 688: 685: 678: 672: 669: 668: 665: 662: 661: 658: 655: 654: 652: 647: 642: 636: 633: 632: 629: 626: 625: 622: 619: 618: 616: 611: 606: 600: 597: 596: 593: 590: 589: 586: 583: 582: 580: 573: 567: 564: 562: 559: 557: 554: 553: 550: 547: 545: 542: 540: 537: 536: 533: 530: 528: 525: 523: 520: 519: 517: 501: 500: 487: 481: 478: 477: 474: 471: 470: 467: 464: 463: 461: 445: 444: 431: 425: 422: 420: 417: 415: 412: 411: 408: 405: 403: 400: 398: 395: 394: 391: 388: 386: 383: 381: 378: 377: 375: 297: 296: 293: 290: 287: 284: 281: 278: 275: 272: 269: 266: 263: 260: 257: 254: 251: 248: 245: 242: 239: 236: 233: 230: 227: 224: 221: 218: 214: 213: 210: 207: 204: 201: 198: 195: 192: 189: 186: 183: 180: 177: 174: 171: 168: 165: 162: 159: 156: 153: 150: 147: 144: 141: 138: 135: 121: 118: 107:Lester S. Hill 105:. Invented by 103:linear algebra 77: 76: 31: 29: 22: 15: 13: 10: 9: 6: 4: 3: 2: 5168: 5157: 5154: 5153: 5151: 5132: 5124: 5123: 5120: 5114: 5113:Steganography 5111: 5109: 5106: 5104: 5101: 5099: 5096: 5094: 5091: 5089: 5086: 5084: 5081: 5079: 5076: 5074: 5071: 5069: 5068:Stream cipher 5066: 5064: 5061: 5059: 5056: 5055: 5053: 5049: 5043: 5040: 5038: 5035: 5033: 5030: 5028: 5027:Onion routing 5025: 5023: 5020: 5018: 5015: 5013: 5010: 5008: 5007:Shared secret 5005: 5003: 5000: 4998: 4995: 4993: 4990: 4988: 4985: 4983: 4980: 4978: 4975: 4973: 4970: 4968: 4965: 4963: 4960: 4958: 4955: 4953: 4950: 4947: 4944: 4939: 4936: 4935: 4934: 4931: 4929: 4926: 4924: 4921: 4919: 4916: 4914: 4911: 4909: 4906: 4904: 4903:Key generator 4901: 4899: 4896: 4894: 4891: 4889: 4886: 4884: 4881: 4877: 4874: 4872: 4869: 4868: 4867: 4866:Hash function 4864: 4862: 4859: 4857: 4854: 4852: 4849: 4847: 4844: 4842: 4841:Cryptanalysis 4839: 4837: 4834: 4830: 4827: 4826: 4825: 4822: 4820: 4817: 4815: 4812: 4811: 4809: 4805: 4801: 4794: 4789: 4787: 4782: 4780: 4775: 4774: 4771: 4767: 4753: 4750: 4748: 4745: 4742: 4738: 4734: 4731: 4729: 4726: 4724: 4721: 4720: 4718: 4716:Cryptanalysis 4714: 4708: 4705: 4703: 4700: 4698: 4695: 4694: 4692: 4690: 4689:Steganography 4686: 4680: 4677: 4675: 4672: 4670: 4667: 4666: 4664: 4662: 4658: 4648: 4645: 4643: 4640: 4638: 4635: 4633: 4630: 4628: 4625: 4623: 4620: 4618: 4615: 4613: 4610: 4608: 4605: 4604: 4602: 4598: 4592: 4589: 4587: 4584: 4582: 4579: 4577: 4574: 4572: 4569: 4568: 4566: 4564: 4563:Transposition 4560: 4554: 4551: 4549: 4546: 4544: 4541: 4539: 4536: 4534: 4531: 4529: 4526: 4524: 4521: 4519: 4516: 4514: 4511: 4509: 4506: 4504: 4501: 4500: 4498: 4496: 4492: 4486: 4483: 4481: 4478: 4476: 4473: 4472: 4470: 4466: 4460: 4457: 4455: 4452: 4450: 4447: 4445: 4442: 4440: 4437: 4435: 4432: 4431: 4429: 4427: 4423: 4417: 4414: 4412: 4409: 4407: 4404: 4402: 4399: 4398: 4396: 4394: 4390: 4387: 4383: 4379: 4375: 4368: 4363: 4361: 4356: 4354: 4349: 4348: 4345: 4341: 4337: 4330: 4326: 4323: 4319: 4316: 4312: 4311: 4307: 4302: 4298: 4294: 4293: 4288: 4285: 4281: 4278: 4274: 4270: 4269: 4265: 4261: 4260:Trifid cipher 4258: 4256: 4253: 4251: 4248: 4247: 4246: 4240: 4238: 4236: 4232: 4226: 4223: 4218: 4213: 4211: 4207: 4199: 4197: 4183: 4180: 4175: 4171: 4167: 4144: 4136: 4132: 4127: 4123: 4120: 4117: 4111: 4103: 4099: 4094: 4090: 4087: 4084: 4075: 4071: 4067: 4064: 4061: 4050: 4046: 4041: 4037: 4034: 4031: 4025: 4017: 4013: 4008: 4004: 4001: 3998: 3989: 3985: 3981: 3978: 3975: 3965: 3961: 3956: 3948: 3947: 3946: 3929: 3921: 3917: 3912: 3908: 3905: 3902: 3896: 3888: 3884: 3879: 3875: 3872: 3869: 3860: 3856: 3852: 3849: 3846: 3836: 3832: 3827: 3819: 3818: 3817: 3812: 3793: 3785: 3781: 3776: 3772: 3769: 3766: 3760: 3752: 3748: 3743: 3739: 3736: 3733: 3724: 3720: 3716: 3713: 3710: 3700: 3696: 3691: 3683: 3682: 3681: 3676: 3672: 3668: 3664: 3660: 3656: 3652: 3634: 3630: 3626: 3599: 3595: 3590: 3583: 3578: 3574: 3565: 3561: 3541: 3537: 3532: 3522: 3520: 3516: 3512: 3504: 3502: 3500: 3496: 3492: 3488: 3484: 3479: 3478:little time. 3462: 3458: 3449: 3445: 3437: 3420: 3417: 3414: 3411: 3403: 3397: 3390: 3384: 3379: 3374: 3368: 3361: 3355: 3345: 3339: 3332: 3326: 3321: 3316: 3310: 3303: 3297: 3288: 3287: 3286: 3265: 3261: 3251: 3245: 3238: 3232: 3227: 3222: 3216: 3209: 3203: 3198: 3193: 3187: 3180: 3174: 3167: 3161: 3156: 3149: 3144: 3138: 3129: 3128: 3112: 3105: 3101: 3091: 3085: 3078: 3072: 3067: 3062: 3056: 3049: 3043: 3038: 3033: 3027: 3020: 3014: 3007: 3001: 2996: 2989: 2984: 2978: 2969: 2968: 2967: 2948: 2942: 2935: 2929: 2924: 2919: 2913: 2906: 2900: 2890: 2884: 2877: 2871: 2866: 2861: 2855: 2848: 2842: 2834: 2831: 2828: 2825: 2818: 2817: 2798: 2794: 2784: 2778: 2773: 2766: 2761: 2755: 2750: 2745: 2739: 2734: 2727: 2722: 2716: 2711: 2708: 2703: 2697: 2692: 2685: 2680: 2674: 2667: 2664: 2660: 2656: 2651: 2648: 2644: 2636: 2635: 2634: 2616: 2613: 2605: 2602: 2599: 2596: 2593: 2581: 2576: 2561: 2555: 2550: 2547: 2540: 2537: 2532: 2526: 2519: 2516: 2508: 2505: 2502: 2499: 2496: 2490: 2485: 2482: 2476: 2470: 2465: 2458: 2453: 2447: 2437: 2433: 2415: 2411: 2407: 2404: 2399: 2396: 2392: 2388: 2383: 2380: 2376: 2372: 2350: 2347: 2343: 2334: 2313: 2307: 2300: 2294: 2289: 2284: 2278: 2271: 2265: 2255: 2249: 2242: 2236: 2231: 2226: 2220: 2213: 2207: 2198: 2197: 2196: 2175: 2171: 2161: 2155: 2148: 2142: 2137: 2132: 2126: 2119: 2113: 2106: 2100: 2095: 2088: 2083: 2077: 2068: 2067: 2051: 2044: 2040: 2030: 2024: 2017: 2011: 2006: 2001: 1995: 1988: 1982: 1975: 1969: 1964: 1957: 1952: 1946: 1937: 1936: 1935: 1916: 1910: 1903: 1897: 1892: 1887: 1881: 1874: 1868: 1858: 1852: 1845: 1839: 1834: 1829: 1823: 1816: 1810: 1802: 1799: 1796: 1793: 1786: 1785: 1784: 1765: 1759: 1754: 1747: 1742: 1736: 1731: 1728: 1721: 1720: 1719: 1713: 1711: 1709: 1704: 1690: 1687: 1684: 1681: 1678: 1656: 1652: 1648: 1645: 1618: 1614: 1606: 1603: 1600: 1597: 1591: 1588: 1585: 1582: 1579: 1576: 1573: 1567: 1564: 1558: 1555: 1552: 1549: 1546: 1543: 1540: 1534: 1531: 1525: 1522: 1519: 1516: 1513: 1510: 1507: 1501: 1498: 1493: 1487: 1482: 1477: 1470: 1465: 1460: 1453: 1448: 1443: 1437: 1428: 1427: 1426: 1423: 1416: 1412: 1408: 1407: 1406: 1403: 1382: 1378: 1368: 1362: 1355: 1348: 1342: 1337: 1332: 1326: 1319: 1312: 1306: 1301: 1296: 1290: 1283: 1276: 1270: 1263: 1257: 1252: 1247: 1240: 1235: 1230: 1223: 1218: 1213: 1207: 1198: 1197: 1196: 1177: 1171: 1166: 1161: 1154: 1149: 1144: 1137: 1132: 1127: 1121: 1116: 1109: 1105: 1095: 1092: 1086: 1080: 1075: 1070: 1063: 1058: 1053: 1046: 1041: 1036: 1030: 1020: 1019: 1018: 1016: 1004: 996: 994: 992: 988: 984: 980: 957: 953: 943: 937: 930: 923: 917: 912: 907: 901: 894: 887: 881: 876: 871: 865: 858: 851: 845: 838: 832: 827: 822: 815: 810: 805: 798: 793: 788: 782: 773: 772: 771: 752: 746: 739: 732: 726: 717: 716: 715: 713: 690: 686: 676: 670: 663: 656: 650: 645: 640: 634: 627: 620: 614: 609: 604: 598: 591: 584: 578: 571: 565: 560: 555: 548: 543: 538: 531: 526: 521: 515: 506: 505: 504: 485: 479: 472: 465: 459: 450: 449: 448: 429: 423: 418: 413: 406: 401: 396: 389: 384: 379: 373: 364: 363: 362: 351: 349: 345: 341: 337: 332: 330: 326: 323: 319: 316: 312: 308: 304: 294: 291: 288: 285: 282: 279: 276: 273: 270: 267: 264: 261: 258: 255: 252: 249: 246: 243: 240: 237: 234: 231: 228: 225: 222: 219: 216: 215: 211: 208: 205: 202: 199: 196: 193: 190: 187: 184: 181: 178: 175: 172: 169: 166: 163: 160: 157: 154: 151: 148: 145: 142: 139: 136: 133: 132: 129: 127: 119: 117: 115: 110: 108: 104: 100: 96: 92: 83: 73: 70: 62: 59:February 2012 52: 48: 42: 41: 35: 30: 21: 20: 5063:Block cipher 4908:Key schedule 4898:Key exchange 4888:Kleptography 4851:Cryptosystem 4800:Cryptography 4622:One-time pad 4537: 4495:Substitution 4290: 4283: 4272: 4255:Bifid cipher 4244: 4227: 4214: 4210:bifid cipher 4203: 4159: 3944: 3810: 3808: 3674: 3666: 3662: 3654: 3650: 3563: 3559: 3523: 3508: 3494: 3480: 3441: 3284: 2965: 2577: 2431: 2332: 2330: 2194: 1933: 1782: 1717: 1705: 1637: 1424: 1420: 1404: 1401: 1194: 1000: 990: 986: 976: 769: 709: 502: 446: 352: 343: 339: 333: 321: 317: 306: 302: 300: 123: 111: 94: 88: 65: 56: 37: 5051:Mathematics 5042:Mix network 4674:Code talker 4553:Running key 4485:Four-square 4292:Cryptologia 3285:Therefore, 2331:The matrix 1415:determinant 309:-component 95:Hill cipher 51:introducing 5002:Ciphertext 4972:Decryption 4967:Encryption 4928:Ransomware 4723:Cryptogram 4617:Kama Sutra 4586:Rail fence 4581:Myszkowski 4528:Chaocipher 4480:Two-square 4459:VIC cipher 4411:Trithemius 4266:References 3680:). It is 3524:There are 3483:non-linear 997:Decryption 712:ciphertext 346:matrices ( 327:, against 315:invertible 120:Encryption 34:references 4992:Plaintext 4647:Solitaire 4385:by family 4297:CiteSeerX 4181:− 4121:− 4112:⋯ 4088:− 4065:− 4035:− 4026:⋯ 4002:− 3979:− 3906:− 3897:⋯ 3873:− 3850:− 3770:− 3761:⋯ 3737:− 3714:− 3619:or about 3584:⁡ 3511:key space 3487:diffusion 3409:→ 3351:→ 3228:≡ 3068:≡ 2896:→ 2838:→ 2751:≡ 2709:≡ 2665:− 2657:≡ 2649:− 2614:− 2600:− 2548:− 2538:− 2517:− 2503:− 2483:− 2397:− 2381:− 2348:− 2261:→ 2138:≡ 2007:≡ 1864:→ 1806:→ 1688:× 1604:≡ 1589:⋅ 1583:− 1577:⋅ 1556:⋅ 1550:− 1544:⋅ 1532:− 1523:⋅ 1517:− 1511:⋅ 1338:≡ 1117:≡ 1093:− 985:, and an 983:diffusion 913:≡ 646:≡ 101:based on 5150:Category 5131:Category 5037:Kademlia 4997:Codetext 4940:(CSPRNG) 4735:(Units: 4571:Columnar 4518:Beaufort 4475:Playfair 4449:Tap code 4444:Nihilist 4416:Vigenère 4241:See also 4206:Playfair 3515:key size 3438:Security 114:matrices 4807:General 4513:Autokey 4401:Alberti 4382:Ciphers 4208:or the 3566:. Thus 3499:Twofish 2436:formula 1714:Example 1411:inverse 979:Shannon 342:× 329:modulus 320:× 217:Number 134:Letter 47:improve 4918:Keygen 4702:Grille 4642:Slidex 4576:Double 4543:Pigpen 4523:Caesar 4508:Atbash 4503:Affine 4468:Square 4454:Trifid 4434:ADFGVX 4406:Enigma 4217:patent 3816:)) is 3448:linear 1015:modulo 348:modulo 325:matrix 311:vector 126:modulo 93:, the 36:, but 4948:(PRN) 4697:Bacon 4661:Codes 4612:DRYAD 4607:BATCO 4600:Other 4591:Route 4548:ROT13 4533:Great 4439:Bifid 3673:GL(n, 1708:prime 97:is a 4739:and 4707:Null 4679:Poem 4669:Book 4538:Hill 4168:4.64 3509:The 1718:Let 1671:and 4741:Nat 4737:Ban 4301:PDF 4299:) ( 4277:PDF 4184:1.7 3627:4.7 3575:log 3497:in 3491:AES 3262:mod 3217:171 3210:323 3125:and 3102:mod 3057:212 3050:241 2795:mod 2172:mod 2064:and 2041:mod 1615:mod 1601:441 1379:mod 1327:539 1320:574 1313:260 1106:mod 1009:VIV 981:'s 954:mod 902:325 895:216 687:mod 635:319 628:222 357:NQK 336:key 295:25 89:In 5152:: 4133:13 4100:13 4076:13 3957:26 3918:13 3885:13 3861:13 3828:13 3814:13 3665:Ă— 3653:Ă— 3591:26 3562:Ă— 3533:26 3340:15 3333:11 3266:26 3246:15 3239:11 3188:19 3157:20 3150:17 3145:15 3106:26 2997:20 2990:17 2985:15 2943:19 2799:26 2774:20 2767:17 2762:15 2735:24 2728:23 2693:24 2686:23 2250:19 2176:26 2156:19 2127:15 2120:11 2045:26 1911:15 1904:11 1691:13 1679:26 1646:25 1619:26 1607:25 1592:20 1586:16 1580:17 1574:13 1559:20 1553:10 1547:15 1541:13 1535:24 1526:17 1520:10 1514:15 1508:16 1488:15 1483:17 1478:20 1471:10 1466:16 1461:13 1449:24 1383:26 1363:19 1284:14 1277:15 1253:12 1248:21 1241:21 1231:21 1224:10 1167:12 1162:21 1155:21 1145:21 1138:10 1110:26 1081:15 1076:17 1071:20 1064:10 1059:16 1054:13 1042:24 958:26 938:13 888:31 866:19 833:15 828:17 823:20 816:10 811:16 806:13 794:24 747:19 691:26 664:14 657:15 621:67 599:19 566:15 561:17 556:20 549:10 544:16 539:13 527:24 480:19 424:15 419:17 414:20 407:10 402:16 397:13 385:24 292:24 289:23 286:22 283:21 280:20 277:19 274:18 271:17 268:16 265:15 262:14 259:13 256:12 253:11 250:10 212:Z 116:. 4792:e 4785:t 4778:v 4743:) 4366:e 4359:t 4352:v 4327:" 4320:" 4313:" 4303:) 4279:) 4219:( 4176:2 4172:n 4145:. 4142:) 4137:n 4128:/ 4124:1 4118:1 4115:( 4109:) 4104:2 4095:/ 4091:1 4085:1 4082:( 4079:) 4072:/ 4068:1 4062:1 4059:( 4056:) 4051:n 4047:2 4042:/ 4038:1 4032:1 4029:( 4023:) 4018:2 4014:2 4009:/ 4005:1 3999:1 3996:( 3993:) 3990:2 3986:/ 3982:1 3976:1 3973:( 3966:2 3962:n 3930:. 3927:) 3922:n 3913:/ 3909:1 3903:1 3900:( 3894:) 3889:2 3880:/ 3876:1 3870:1 3867:( 3864:) 3857:/ 3853:1 3847:1 3844:( 3837:2 3833:n 3811:Z 3794:. 3791:) 3786:n 3782:2 3777:/ 3773:1 3767:1 3764:( 3758:) 3753:2 3749:2 3744:/ 3740:1 3734:1 3731:( 3728:) 3725:2 3721:/ 3717:1 3711:1 3708:( 3701:2 3697:n 3692:2 3678:2 3675:Z 3667:n 3663:n 3655:n 3651:n 3635:2 3631:n 3607:) 3600:2 3596:n 3587:( 3579:2 3564:n 3560:n 3542:2 3538:n 3495:g 3463:2 3459:n 3433:. 3421:P 3418:L 3415:E 3412:H 3404:) 3398:P 3391:L 3385:( 3380:, 3375:) 3369:E 3362:H 3356:( 3346:) 3327:( 3322:, 3317:) 3311:4 3304:7 3298:( 3269:) 3259:( 3252:) 3233:( 3223:) 3204:( 3199:= 3194:) 3181:0 3175:( 3168:) 3162:9 3139:( 3113:, 3109:) 3099:( 3092:) 3086:4 3079:7 3073:( 3063:) 3044:( 3039:= 3034:) 3028:8 3021:7 3015:( 3008:) 3002:9 2979:( 2949:) 2936:0 2930:( 2925:, 2920:) 2914:8 2907:7 2901:( 2891:) 2885:T 2878:A 2872:( 2867:, 2862:) 2856:I 2849:H 2843:( 2835:T 2832:A 2829:I 2826:H 2802:) 2792:( 2785:) 2779:9 2756:( 2746:) 2740:3 2723:5 2717:( 2712:3 2704:) 2698:3 2681:5 2675:( 2668:1 2661:9 2652:1 2645:K 2631:. 2617:1 2610:) 2606:c 2603:b 2597:d 2594:a 2591:( 2562:) 2556:a 2551:c 2541:b 2533:d 2527:( 2520:1 2513:) 2509:c 2506:b 2500:d 2497:a 2494:( 2491:= 2486:1 2477:) 2471:d 2466:c 2459:b 2454:a 2448:( 2432:K 2416:2 2412:I 2408:= 2405:K 2400:1 2393:K 2389:= 2384:1 2377:K 2373:K 2351:1 2344:K 2333:K 2314:) 2308:T 2301:A 2295:( 2290:, 2285:) 2279:I 2272:H 2266:( 2256:) 2243:0 2237:( 2232:, 2227:) 2221:8 2214:7 2208:( 2179:) 2169:( 2162:) 2149:0 2143:( 2133:) 2114:( 2107:) 2101:5 2096:2 2089:3 2084:3 2078:( 2052:, 2048:) 2038:( 2031:) 2025:8 2018:7 2012:( 2002:) 1996:4 1989:7 1983:( 1976:) 1970:5 1965:2 1958:3 1953:3 1947:( 1917:) 1898:( 1893:, 1888:) 1882:4 1875:7 1869:( 1859:) 1853:P 1846:L 1840:( 1835:, 1830:) 1824:E 1817:H 1811:( 1803:P 1800:L 1797:E 1794:H 1766:) 1760:5 1755:2 1748:3 1743:3 1737:( 1732:= 1729:K 1685:2 1682:= 1657:2 1653:5 1649:= 1622:) 1612:( 1598:= 1595:) 1571:( 1568:1 1565:+ 1562:) 1538:( 1529:) 1505:( 1502:6 1499:= 1494:| 1454:1 1444:6 1438:| 1386:) 1376:( 1369:) 1356:2 1349:0 1343:( 1333:) 1307:( 1302:= 1297:) 1291:7 1271:( 1264:) 1258:8 1236:8 1219:5 1214:8 1208:( 1178:) 1172:8 1150:8 1133:5 1128:8 1122:( 1113:) 1103:( 1096:1 1087:) 1047:1 1037:6 1031:( 1011:/ 1007:/ 991:n 987:n 961:) 951:( 944:) 931:8 924:5 918:( 908:) 882:( 877:= 872:) 859:0 852:2 846:( 839:) 799:1 789:6 783:( 753:) 740:0 733:2 727:( 694:) 684:( 677:) 671:7 651:( 641:) 615:( 610:= 605:) 592:2 585:0 579:( 572:) 532:1 522:6 516:( 486:) 473:2 466:0 460:( 430:) 390:1 380:6 374:( 359:/ 355:/ 344:n 340:n 322:n 318:n 307:n 303:n 247:9 244:8 241:7 238:6 235:5 232:4 229:3 226:2 223:1 220:0 209:Y 206:X 203:W 200:V 197:U 194:T 191:S 188:R 185:Q 182:P 179:O 176:N 173:M 170:L 167:K 164:J 161:I 158:H 155:G 152:F 149:E 146:D 143:C 140:B 137:A 72:) 66:( 61:) 57:( 43:.

Index

references
inline citations
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classical cryptography
polygraphic substitution cipher
linear algebra
Lester S. Hill
matrices
modulo
vector
invertible
matrix
modulus
key
modulo
ciphertext
Shannon
diffusion
inverse matrix
modulo
inverse
determinant
prime
formula
modular multiplicative inverse
known-plaintext attack
linear

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