-----Message d'origine----- De�: Cornel Maftuleac [mailto:[EMAIL PROTECTED] Envoy�: mardi 12 octobre 2004 16:09 ��: [EMAIL PROTECTED] Objet�: RSA Public key encryption.
Hello all. I have the following questions: I have to encrypt using RSAES_OAEP_SHA a block of data. Data length is larger then the admisible length for the selected key and length. For example for a key length of 512bits we can encode 22 bytes of data. For this purpose I am using the following well-known scheme: 1. Encrypt the message using a symmetric cipher. 2. Encrypt the symetric's key using RSA publik key, and append it to the encrypted message in first step. [MSG]sk + [sk]pk sk - symmetric key pk - assymmetric public key This all works fine, but until we have cases when the key itself is bigger than the admisible msg size for RSA. What to do in this case?:) The easyest way is to split symmetric key in blocks not bigger than the max admisible msg length for the selected key, and encrypt every block with RSA public key, and along with a biggger assymmetric key, 1024, 4098 etc. How do you think this is secure enough? Maybe there exist other ways of doing this? ____________ Virus checked by G DATA AntiVirusKit Version: BD 15.0.47 from 09.10.2004 Virus news: www.antiviruslab.com
