I came across an issue while encrypting a xml using Apache XML Securty.
Error Occured when the code Reached the below line.
//cipher.doFinal(ContainerDoc,PayloadDoc.getRootElement());
When i digged in to that issue a lot of things got cleared in a much better way .
I am not going to write all basics of Asymmetric Encryption.I did an Asymmetric Encryption as two Step Process as Described by many Articles on Web.
a. Generated a AES128 Symmetric key and encrypted the Data
b. Encrypted the Symmetric key with a Public Key.
I was aware of only one Reason for the above Steps. As the Asymmetric Encryption is Expensive the symmetric and Asymmetric Technique described above will Increase the Performance and will make the System More scalable.
But that's not the Only One Reason.
Another Very Important Reason. The x.509V3 Certificates which has RSA 1024 bits key, cannot Encrypt more than 117 bytes.
So,Use an Asymmetric key to split the data into blocks and encrypt it(this could be done on data of any size)
How this 117 bytes is calculated is given in the below link?
http://www.owasp.org/index.php/Digital_Signature_Implementation_in_Java
