Basic kryptering
Tekst:
Krypteret tekst:
868 135 965 322 570 103 993 210 818 1081 257 158 661 136 341 399 305 180 355 351 506 972 484
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
802 21 848 219 538 6 891 178 707 971 156 113 545 31 232 298 260 73 254 230 394 875 384 481 621 487 911 944 733 131 409 97 886 109 49 200 650 697 174 669 341 745 193 206 408 434 408 603 488 493 379 233 544 363 303 312 745 70 910 578 512 979 724 387 16 856 943 44 419 842 354 875 243 363 252 903 319 470 253 538 888 807 45 677 131 899 129 483 389 334 645 350 559 898 772 739 744 246 514 63 961 7 327 737 577 530 710 390 198 750 806 806 297 321 212 545 615 376 212 154 480 657 143 874 918 283 587 426 341 138 441 222 435 891 968 511 982 24 910 258 703 3 300 818 781 31 293 830 164 54 47 252 150 715 686 538 795 335 203 601 561 807 391 405 79 570 53 618 296 489 612 220 164 845 220 279 378 275 571 311 230 639 98 645 115 511 346 337 480 892 963 686 459 867 427 365 568 987 533 713 53 592 200 764 521 173 273 721 94 949 936 320 181 420 104 677 310 333 842 454 300 823 142 148 268 774 831 203 687 197 909 221 42 477 356 198 278 101 119 471 231 74 815 898 791 707 61 131 586 978 971 690 635 501 522 84 874 195 755 397 780 912 580 334 17 74 430 607 216 562 879 581 474 566 480 221 886 531 431 6 454 367 576 507 454 136 738 206 48 777 734 115 822 404 437 522 675 722 420 372 181 379 428 747 951 717 172 374 176 890 714 234 464 840 623 995 639 906 197 407 860 103 349 250 97 902 205 268 327 128 88 12 745 142 207 246 261 755 98 887 558 161 244 751 968 992 273 1 241 89 776 149 889 203 874 766 309 303 685 721 357 937 177 532 201 348 229 209 613 937 680 12 677 144 291 427 563 84 855 984 747 875 312 958 643 835 837 710 158 305 786 780 68 231 369 103 667 133 173 782 428 411 6 230 914 277 206 389 388 702 228 249 305 361 282 179 387 118 331 631 459 272 714 34 242 758 852 875 225 645 466 251 461 820 109 661 520 666 385 831 516 796 706 185 21 624 89 975 524 766 341 560 728 433 905 936 495 285 910 410 151 616 257 193 91 679 901 659 2 952 113 708 682 961 443 739 829 555 914 9 116 467 102 844 258 414 179 62 506 993 3 885 592 308 54 945 653 241 974 89
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