Checksum

  • Thread starter Thread starter Guest
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G

Guest

hi,

need help here, does anyone know how to use or does any one have the code
for checksum? I want to checksum a string to be sent using udp and checksum
it again when received.. does anyone know the code for checksum? Thanks i
would really really appreciate it. Thanks in advance..
 
I'm assuming you mean the CHECKSUM function in SQL server; if not disregard.

Anyways ... no, no one has the code for CHICKSUM. Well the SQL Server team
must, but you shouldn't rely on it anyways - a hash function like CHECKSUM or
..NET's GetHashCode() can change from version to version so you shouldn't rely
on it.

What you should do is use a well known hash algorithym like MD5 or SHA1, and
use that for your comparisons. See the System.Security.Cryptography namespace
in .NET SDK.
 
The easiest way is use Hash functions like MD5, SHA1.
Check out them in System.Security.Cryptography namespace.
Note that MD5 generates a byte array of 128 bytes (SHA1, 160 bytes).
You can convert them to hex string if needed.
 
I mean bits, not bytes. And someone else already answered above, did
not notice.
 
Rain said:
hi,

need help here, does anyone know how to use or does any one have the code
for checksum? I want to checksum a string to be sent using udp and
checksum it again when received.. does anyone know the code for checksum?
Thanks i would really really appreciate it. Thanks in advance..
Click to expand...

Hi,

There are a number of checksum functions available, each with their merits
(and their disadvantages). Hashing (as has been mentioned) is a popular
method of creating a checksum, but there are also algorithms such as CRC -
the Cyclic Redundancy Check.

For your reference, here is an URL to an implementation of CRC:
http://www.codeproject.com/csharp/marcelcrcencoding.asp
 
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