.model small
.data
    value db 'sanjay', '$'
    v_size dw $-value
    encrypt db 7 dup (?)
    decrypt db 7 dup (?)

.code
begin:
    mov ax, @data
    mov ds, ax

    mov es, ax
    lea si, value
    lea di, encrypt

    mov cx, v_size
    dec cx

    mov ah, 09h
    lea dx, valueint 21h

counter1:
    mov ah, 0000h
    mov al, [si]
    add al, 01h
    mov [di], al
    inc di
    inc si
    loop counter1
        mov [di], '$'

    mov ah, 09h
    lea dx, encrypt
    int 21h

    lea si, encrypt
    lea di, decrypt    
    mov cx, v_size
    dec cx


counter2:
    mov ah, 0000h
    mov al, [si]
    sub al, 01h
    mov [di], al
    inc di
    inc si
    loop counter2
        mov [di], '$'

    mov ah, 09h
    lea dx, decrypt
    int 21h

.exit
end begin