Basic kryptering
Tekst:
Krypteret tekst:
475 673 653 312 1013 621 521 633 1004 432 502 556 567 745 339 381 800 180 240 226 519 629 576
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
409 559 536 209 981 524 419 601 893 322 401 511 451 640 230 280 755 73 139 105 407 532 476 220 38 190 9 815 850 160 465 634 926 602 342 572 973 749 293 877 80 365 707 928 936 457 9 311 344 332 800 180 507 306 527 571 631 756 406 753 290 121 783 97 40 481 469 200 574 843 482 101 45 941 625 656 729 152 940 935 948 990 154 622 895 362 550 678 845 43 741 306 912 340 600 650 246 290 656 26 595 35 668 534 354 62 877 268 298 477 937 18 491 100 703 603 408 972 133 271 877 226 102 500 812 563 26 215 271 442 788 230 946 449 628 220 531 147 362 124 473 73 515 827 801 549 261 768 498 14 680 104 690 535 364 893 416 533 459 77 869 471 157 115 449 161 313 909 189 582 364 476 215 152 751 614 914 984 26 644 561 374 708 329 285 826 918 534 618 923 105 285 894 957 15 73 420 794 589 15 757 870 712 477 20 494 172 540 990 982 293 59 792 244 31 412 262 481 654 907 696 671 427 808 683 915 749 802 495 705 298 480 812 457 818 189 81 715 331 877 762 816 314 690 510 759 951 505 203 811 170 764 597 261 649 541 469 740 809 517 136 535 321 76 800 607 497 823 841 644 229 774 81 835 483 566 176 956 490 551 593 415 89 77 878 124 83 229 598 748 723 173 847 186 913 392 817 664 163 336 758 999 609 258 881 72 674 24 382 833 905 725 413 900 953 925 280 26 653 338 862 683 301 625 383 560 326 915 363 698 683 58 650 994 943 365 487 176 647 424 905 490 429 80 185 954 634 811 535 492 186 334 336 576 158 871 144 181 363 651 137 532 181 442 800 876 114 283 80 356 955 519 73 791 544 38 637 445 514 654 167 890 377 504 296 785 256 457 169 432 123 870 932 383 542 258 435 936 724 662 405 518 120 634 744 760 595 553 349 285 337 824 394 772 496 689 331 463 245 515 362 872 993 602 692 312 518 184 995 72 944 424 5 460 516 676 735 437 306 591 485 402 533 44 970 26 377 485 510 166 520 688 356 789 313 48 764 898 102 920 362 3 27 948 200 887 390 616 855 812 444 378 189 914 83 119 764 582 866 759 44 122 609 979 855 599 86 874 653 984 388 505 919 618 822 707 569 179 956 589
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