Basic kryptering
Tekst:
Krypteret tekst:
781 822 532 721 815 220 673 284 548 300 465 470 491 179 570 333 418 939 500 573 313 793 1053
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
715 708 415 618 783 123 571 252 437 190 364 425 375 74 461 232 373 832 399 452 201 696 953 29 472 351 99 573 570 264 964 99 440 51 41 520 274 854 888 952 961 4 239 569 19 425 9 65 329 208 436 980 999 492 486 460 639 167 775 452 457 359 594 631 843 411 301 615 498 348 845 187 585 386 723 259 181 225 763 280 103 688 94 744 427 184 925 950 689 175 379 494 717 918 529 517 984 233 152 304 709 682 321 94 634 288 735 202 352 341 508 895 827 670 244 608 566 967 323 532 210 488 73 38 109 931 432 630 69 538 82 655 807 478 205 410 356 554 354 765 953 320 557 168 589 690 955 860 777 65 480 83 313 633 303 774 202 243 734 283 642 767 137 66 70 574 412 939 449 186 45 361 170 53 91 220 770 465 280 575 848 529 564 797 261 305 797 682 221 289 438 312 127 433 598 326 192 431 420 183 128 612 636 433 633 638 603 188 948 224 976 957 39 720 940 954 970 336 150 721 281 557 291 419 496 728 671 307 633 537 169 783 654 608 787 182 851 733 670 744 341 404 26 423 401 314 952 503 279 875 850 702 228 446 629 471 873 630 757 705 966 565 754 985 387 921 376 913 298 116 836 170 505 871 759 181 294 793 437 764 722 939 772 90 724 31 121 297 557 826 718 68 427 796 133 986 586 127 989 444 720 797 159 143 290 743 355 528 52 849 315 109 428 320 242 232 903 612 874 464 138 593 691 976 38 68 420 493 622 923 274 81 97 790 947 633 856 631 729 448 358 446 986 900 335 222 189 214 43 498 625 450 360 976 224 672 638 539 102 431 819 341 420 833 950 11 570 240 584 149 664 669 209 664 982 149 151 211 217 667 299 708 597 297 435 871 215 328 977 901 473 515 590 614 361 53 561 788 221 744 125 705 339 917 527 959 971 287 238 935 913 546 541 750 765 420 115 840 706 817 954 121 659 941 631 143 411 84 883 596 323 552 522 476 916 95 415 83 719 189 354 440 373 193 649 260 588 460 867 303 205 603 806 143 223 595 915 232 733 753 41 321 928 51 985 219 952 876 834 617 648 704 659 548 96 364 483 254 712 234 627 273 503 973 772 825 379 701 446 123 548 806 578 156 681 248 60 201 343 80
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