Basic kryptering
Tekst:
Krypteret tekst:
282 369 455 723 701 109 688 136 637 291 962 605 342 335 363 643 579 840 483 580 650 520 1046
De-Krypteret tekst:
Brug af one-time-keypad
One-time pad
In cryptography, the one-time pad (OTP) is an encryption technique that cannot be cracked, but requires the use of a single-use pre-shared key that is larger than or equal to the size of the message being sent. In this technique, a plaintext is paired with a random secret key (also referred to as a one-time pad). Then, each bit or character of the plaintext is encrypted by combining it with the corresponding bit or character from the pad using modular addition. The resulting ciphertext will be impossible to decrypt or break if the following four conditions are met
- The key must be at least as long as the plaintext.
- The key must be truly random.
- The key must never be reused in whole or in part.
- The key must be kept completely secret by the communicating parties.
It has also been mathematically proven that any cipher with the property of perfect secrecy must use keys with effectively the same requirements as OTP keys. Digital versions of one-time pad ciphers have been used by nations for critical diplomatic and military communication, but the problems of secure key distribution make them impractical for most applications.
One-time-use-key-pad. Max 500 tegn
216 255 338 620 669 12 586 104 526 181 861 560 226 230 254 542 534 733 382 459 538 423 946 530 377 888 362 454 236 792 504 678 776 112 140 586 934 489 759 970 268 882 532 904 741 355 577 872 11 313 766 894 647 924 929 831 412 381 904 496 847 553 779 91 689 279 454 992 575 176 786 448 905 251 607 407 529 345 161 711 414 326 480 922 602 96 651 271 891 515 642 288 394 351 152 323 38 603 869 649 173 843 887 222 131 729 0 680 851 976 31 381 294 383 362 134 168 581 581 314 677 233 996 830 829 461 234 188 554 796 378 834 733 56 676 247 86 420 26 177 950 894 656 103 544 243 513 535 639 249 231 325 375 871 227 411 668 888 89 699 450 793 16 857 634 957 426 720 957 765 416 693 432 513 887 774 64 544 890 540 500 723 580 243 377 184 389 303 215 510 95 509 790 807 188 213 612 755 271 76 777 745 229 952 92 737 962 260 444 857 77 799 682 56 153 358 556 434 989 546 736 115 308 80 179 3 958 853 956 469 958 381 594 793 433 109 886 207 552 512 314 752 868 764 597 505 844 641 568 123 481 149 494 616 373 413 820 374 249 549 565 674 231 422 134 557 526 38 373 237 756 367 11 638 290 303 742 223 958 269 336 960 303 858 707 844 14 853 257 199 699 923 653 59 71 240 969 835 944 77 801 379 716 813 53 348 681 921 615 990 937 993 631 92 833 457 930 826 770 679 428 469 304 344 275 924 839 40 214 505 984 660 48 117 418 852 904 172 463 568 19 510 732 901 956 224 842 192 509 547 142 873 325 958 667 678 465 269 450 60 785 140 53 685 368 699 619 313 351 611 94 473 148 423 433 754 208 717 574 644 297 594 826 564 889 143 376 196 507 854 323 786 156 179 124 66 137 712 799 714 181 648 105 119 806 167 461 996 364 141 959 587 611 228 657 676 59 514 378 478 290 206 738 823 271 644 503 460 673 803 930 541 445 241 211 656 628 577 453 430 180 557 933 942 31 897 212 591 230 859 833 324 588 261 749 23 375 709 400 635 235 783 30 998 284 844 746 418 31 638 55 730 173 458 583 549 878 481 198 870 897 51 534 224 201 490 496 858 735 733 630 863 794 59 520 363 930 142 453 289
I kode er det relativt nemt at lave operationerne. Det er også nemt at udvide til 500+ tegn
Det store problem er udveksling af keys og at holde dem hemmelige