Simple Encryption
Simple Encryption
I have tried to encrypt a string using xor instruction.
I am using x86 asm with emu8086. It displays "Hello World Pello World". It only encrypts the first character. Why is this?
Code:
.model tiny .code org 100h mov ah, 09h mov dx, offset msg int 21h xor msg, 00011000b mov ah, 09h mov dx, offset msg int 21h mov ah,4ch mov al,00 int 21h .data msg db "Hello World $"
Originally Posted by samlarenskoog
I have tried to encrypt a string using xor instruction.
I am using x86 asm with emu8086. It displays "Hello World Pello World". It only encrypts the first character. Why is this?
Code:
.model tiny .code org 100h mov ah, 09h mov dx, offset msg int 21h xor msg, 00011000b mov ah, 09h mov dx, offset msg int 21h mov ah,4ch mov al,00 int 21h .data msg db "Hello World $"
The reason why only first character is XORed is because the xor operator only works on one byte per operation.
