Basic kryptering
Tekst:
Krypteret tekst:
362 1010 337 687 329 262 784 441 733 932 926 290 671 326 143 111 249 831 249 301 904 235 143
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
296 896 220 584 297 165 682 409 622 822 825 245 555 221 34 10 204 724 148 180 792 138 43 840 511 321 23 728 400 991 267 995 49 857 946 109 932 786 274 551 585 870 574 858 391 169 666 427 37 798 736 299 790 17 594 669 822 941 429 104 639 215 750 243 320 232 81 607 86 383 451 793 253 58 993 101 633 816 434 472 945 126 755 13 771 19 481 927 559 567 418 224 448 275 674 973 388 701 931 389 957 702 209 503 345 659 261 324 503 344 448 587 615 748 449 44 275 179 405 777 926 922 959 370 119 462 28 466 672 896 651 636 121 424 518 973 327 433 494 78 7 318 548 299 172 271 163 286 244 914 905 10 481 861 298 931 751 866 37 34 716 555 879 18 815 116 702 606 248 438 593 174 154 222 876 734 638 850 433 687 967 104 503 383 216 557 901 88 257 21 422 89 955 982 122 863 460 341 890 500 42 951 780 923 663 849 492 773 800 830 862 404 54 878 980 305 851 660 728 341 809 677 177 90 112 764 876 723 999 957 34 998 116 679 542 362 617 54 431 771 347 739 169 463 210 28 363 713 897 502 396 92 375 450 211 6 694 477 692 705 380 611 341 660 595 655 740 743 358 815 584 888 225 302 785 984 224 377 443 341 902 713 540 21 319 222 415 954 336 685 438 569 734 413 931 503 312 228 135 676 560 126 647 14 651 798 624 263 929 997 688 230 636 402 384 83 883 335 941 633 263 180 762 157 626 670 763 404 458 548 694 199 144 594 647 233 629 278 382 17 542 349 587 708 440 799 17 763 548 882 417 848 807 366 713 986 245 166 370 400 250 401 880 823 577 160 724 627 441 645 78 816 50 9 812 46 302 708 29 370 127 816 419 801 182 89 616 586 570 230 643 331 637 641 430 360 920 282 602 741 716 817 368 418 177 838 458 851 956 972 776 597 130 931 202 670 623 609 668 309 247 428 806 961 290 763 534 941 335 725 994 171 666 554 802 94 915 701 16 537 319 595 948 567 108 13 686 586 926 546 80 209 451 343 401 898 98 449 944 704 29 466 783 202 917 815 790 212 70 937 14 733 763 601 14 760 840 669 412 83 721 495 341 905 390 524 760 786 0 763 464 441 807 366 65 900 435 629 730 130
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