DATAS SEGMENT
w dw 0
keybuf db 255
db 0
db 255 dup(0) ;定義鍵盤(pán)輸入需要的緩沖區(qū)
DATAS ENDS
STACKS SEGMENT
db 200 dup(?)
STACKS ENDS
Codes SEGMENT
ASSUME CS:Codes,DS:DATAS,SS:STACKS
START:
MOV AX,DATAS
MOV DS,AX
mov dx,offset keybuf ;用0a號(hào)功能，輸入一個(gè)字符串
mov ah,0ah ;用回車(chē)結(jié)束
int 21h
mov dl,0ah ;再進(jìn)行換行，以便在下一行顯示轉(zhuǎn)換后的字符串
mov ah,2
int 21h
; push ax
; push dx
; mov dl,cl
; mov ah,02
; int 21h
; pop dx
; pop ax
mov bx,offset keybuf+1 ;取出字符串的字符個(gè)數(shù)，作為循環(huán)的次數(shù)
mov cl,[bx]
mov ch,0
mov ax,0
again:
inc bx
mov ax,[w]
push bx
mov bx,16
mul bx
pop bx ;是小寫(xiě)字母，則轉(zhuǎn)換為大寫(xiě)字母
mov [w],ax
mov dl,[bx] ;取出一個(gè)字符，
cmp dl,'9'
jbe lab1
cmp dl,'F'
jbe lab2
sub dl,32
lab2: sub dl ,07h
lab1: sub dl,30h
add [w],dx
loop again
mov ax,[w]
mov bx,-1
push bx
mov bx,10
lab3 :mov dx,0
div bx
push dx
cmp ax,0
jnz lab3
lab5: pop dx
cmp dx,-1
jz lab4
add dl,30h
mov ah,02
int 21h
jmp lab5 ;循環(huán)，處理完整個(gè)字符串
lab4: MOV AH,4CH
INT 21H
Codes ENDS
END START
標(biāo)簽：
匯編
上傳時(shí)間：
2015-04-02
上傳用戶：wcc0310
Abstract—In the future communication applications, users
may obtain their messages that have different importance levels
distributively from several available sources, such as distributed
storage or even devices belonging to other users. This
scenario is the best modeled by the multilevel diversity coding
systems (MDCS). To achieve perfect (information-theoretic)
secrecy against wiretap channels, this paper investigates the
fundamental limits on the secure rate region of the asymmetric
MDCS (AMDCS), which include the symmetric case as a special
case. Threshold perfect secrecy is added to the AMDCS model.
The eavesdropper may have access to any one but not more than
one subset of the channels but know nothing about the sources,
as long as the size of the subset is not above the security level.
The question of whether superposition (source separation) coding
is optimal for such an AMDCS with threshold perfect secrecy
is answered. A class of secure AMDCS (S-AMDCS) with an
arbitrary number of encoders is solved, and it is shown that linear
Codes are optimal for this class of instances. However, in contrast
with the secure symmetric MDCS, superposition is shown to
be not optimal for S-AMDCS in general. In addition, necessary
conditions on the existence of a secrecy key are determined as a
design guideline.
標(biāo)簽：
Fundamental
Limits
Secure
Class
on
of
上傳時(shí)間：
2020-01-04
上傳用戶：kddlas
