error: "illegal key size..." thrown when encrypt with RSA

Hello everyone:

I am using vb.net 2003, sqlserver2000 database, and windows 2000
professional OS.

In the program, I encrypt the login user's userid and passed with
RSACryptoServiceProvider. It is work fine in my compute,

but when i set up it on the client computer(which have assembled IE6.0 SP1,
.net framework 1.1 and MDAC 2.7. and the

crytion key displayed in the IE help is 128-bit), it always throw
error:"illegal key size for this algorithm".

Appreciate for any help!!

Thanks in advance.


cqe