function?h?=?hash（inpmeth）?
%?HASH?-?Convert?an?input?variable?into?a?message?digest?using?any?of?
%????????several?common?hash?algorithms?
%?
%?USAGE:?h?=?hash（inp‘meth‘）?
%?
%?inp??=?input?variable?of?any?of?the?following?classes:?
%????????char?uint8?logical?double?single?int8?uint8?
%????????int16?uint16?int32?uint32?int64?uint64?
%?h????=?hash?digest?output?in?hexadecimal?notation?
%?meth?=?hash?algorithm?which?is?one?of?the?following:?
%????????MD2?MD5?SHA-1?SHA-256?SHA-384?or?SHA-512??
%?
%?NOTES:?（1）?If?the?input?is?a?string?or?uint8?variable?it?is?hashed?
%????????????as?usual?for?a?byte?stream.?Other?classes?are?converted?into?
%????????????their?byte-stream?values.?In?other?words?the?hash?of?the?
%????????????following?will?be?identical:?
%?????????????????????‘a(chǎn)bc‘?
%?????????????????????uint8（‘a(chǎn)bc‘）?
%?????????????????????char（[97?98?99]）?
%????????????The?hash?of?the?follwing?will?be?different?from?the?above?
%????????????because?class?“double“?uses?eight?byte?elements:?
%?????????????????????double（‘a(chǎn)bc‘）?
%?????????????????????[97?98?99]?
%????????????You?can?avoid?this?issue?by?making?sure?that?your?inputs?
%????????????are?strings?or?uint8?arrays.?
%????????（2）?The?name?of?the?hash?algorithm?may?be?specified?in?lowercase?
%????????????and/or?without?the?hyphen?if?desired.?For?example?
%????????????h=hash（‘my?text?to?hash‘‘sha256‘）;?
%????????（3）?Carefully?tested?but?no?warranty.?Use?at?your?own?risk.?
%????????（4）?Michael?Kleder?Nov?2005?
%?
%?EXAMPLE:?
%?
%?algs={‘MD2‘‘MD5‘‘SHA-1‘‘SHA-256‘‘SHA-384‘‘SHA-512‘};?
%?for?n=1:6?
%?????h=hash（‘my?sample?text‘a(chǎn)lgs{n}）;?
%?????disp（[algs{n}?‘?（‘?num2str（length（h）*4）?‘?bits）:‘]）?
%?????disp（h）?
%?end?
?
inp=inp（:）;?
%?convert?strings?and?logicals?into?uint8?format?
if?ischar（inp）?||?islogical（inp）?
????inp=uint8（inp）;?
else?%?convert?everything?else?into?uint8?format?without?loss?of?data?
????inp=typecast（inp‘uint8‘）;?
end?
?
%?verify?hash?method?with?some?syntactical?forgiveness:?
meth=upper（meth）;?
switch?meth?
????case?‘SHA1‘?
????????meth=‘SHA-1‘;?
????case?‘SHA256‘?
????????meth=‘SHA-256‘;?
????case?‘SHA384‘?
????????meth=‘SHA-384‘;?
????case?‘SHA512‘?
????????meth=‘SHA-512‘;?
????otherwise?
end?
algs={‘MD2‘‘MD5‘‘SHA-1‘‘SHA-256‘‘SHA-384‘‘SHA-512‘};?
if?isempty（strmatch（methalgs‘exact‘））?
????error（[‘Hash?algorithm?must?be?‘?...?
????????‘MD2?MD5?SHA-1?SHA-256?SHA-384?or?SHA-512‘]）;?
end?
?
%?create?hash?
x=java.security.MessageDigest.getInstance（meth）;?
x.update（inp）;?
h=typecast（x.digest‘uint8‘）;?
h=dec2hex（h）‘;?
if（size（h1））==1?%?remote?possibility:?all?hash?bytes?????h=[repmat（‘0‘[1?size（h2）]）;h];?
end?
h=lower（h（:）‘）;?
clear?x?
return?

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2009-04-25?18:48??基于差分的可逆水印\
?????文件??????527280??2009-03-19?23:41??基于差分的可逆水印\dmrc_difference_expansion.pdf
?????文件????????2814??2009-04-23?20:53??基于差分的可逆水印\hash.m
?????文件???????66616??2009-03-20?10:30??基于差分的可逆水印\lena.bmp
?????文件?????????466??2009-04-23?20:37??基于差分的可逆水印\psnr.m
?????文件????????6291??2009-04-24?14:57??基于差分的可逆水印\Resersible_watermarking.m
?????文件?????2228924??2009-03-19?23:36??基于差分的可逆水印\revwm.pdf
?????文件????????3571??2009-04-22?20:21??基于差分的可逆水印\Rlecode.m
?????文件?????????805??2009-04-16?20:51??基于差分的可逆水印\Rlerecode.m
?????文件??????281088??2009-04-25?18:47??基于差分的可逆水印\程序文檔.doc