passing of short messages in RSA

[LeN via JavaKB.com]

Is RSA algorithm meant for passing short messages only? if so, How would you
say that the message is short or long? i rily nid help..i need supporting
documents about this.. this would help me for my thesis..please...............
.......... thanks!!

 

[Roedy Green]

Is RSA algorithm meant for passing short messages only? if so, How would you
say that the message is short or long? i rily nid help..i need supporting
documents about this.. this would help me for my thesis..please...............
......... thanks!!

Download and play with the Transporter which uses RSA for transporting
short messages. What is short, what is acceptable time are subjective
and depend on what you are doing.

What you can objectively measure is how time varies with key length
and message length, and the ballooning ratios.

See http://mindprod.com/products1.html#TRANSPORTER

I intended it primarily for a lightweight way of Applets to capture
and forward credit card data.

 

[Stefan Schulz]

Is RSA algorithm meant for passing short messages only? if so, How would you
say that the message is short or long? i rily nid help..i need supporting
documents about this.. this would help me for my thesis..please...............
......... thanks!!

If this is for your thesis, you should not trust what "people on the
internet say". However, since i work on a thesis on security too, here is
a hint: Key Cipher vs Load Cipher.

You do not want to encrypt more then one block by means of an asymmetric
cipher. They are slow as hell. Their only benefit is them being, well,
asymmetric. But what is usually very short (rarely even 256 bits)? Right,
symmetric keys. So, if you do not know that your message will fit into the
block-size of RSA or any other asymmetric cipher, exchange a AES (or
whatever algorithm catches your fancy) key by encrypting it
asymmetrically, and encrypt the real data with that key.