public-key-encryption

I am trying to export the keys from a new instance of a ECDiffieHellmanCng object so I can create an instance of it later with the same keys. But I am getting an error when trying to export it. //Create new ECDiffieHellmanCng which automatically creates new keys var ecdh = new ECDiffieHellmanCng(); //Export the keys var privateKey = ecdh.Key.Export(CngKeyBlobFormat.EccPrivateBlob); I am getting a CryptographicException when I call the Export method with the message " The requested operation is not supported. " After putting some breakpoints in the code it looks like it is throwing the

I'm working on a simple program that uses OpenSSL to do basic RSA encryption and decryption. It is working fine for small messages (<16 bytes), but fails for anything over that. I understand that a limitation of public key cryptography is that you cannot encrypt anything longer than the key size. In my case, I'm using a 1024bit key, so I should have 128bytes to work with (maybe slightly less due to padding), correct? If so, that's not what I'm experiencing. Here's the output from my program with 15 bytes: Generating RSA keypair...done. Message to encrypt: 0123456789ABCDE 16 bytes encrypted

I'm testing Synapse and want to know how can I establish a secure connection. I noticed it supports SSL, but I'm not sure whether it suits my needs. I don't have a certificate from CA. I just want to encrypt all data between my server program and client program. Sure, I can encrypt the data myself before sending out. But if SSL can encrypt the data, maybe I can just use it. From what I know, SSL is for "encryption" and "authentication". What I need is only "encryption". Is it possible with Synapse? UPDATE: Thanks for helping from daemon_x and the author of Synapse, Lukas Gebauer, I think I

What is RSA encryption output size when using 2048 bit key (using pkcs1padding). Is it always 256 bytes independent of input size? how can i calculate it for other key sizes? Yes , it is. The output-size should always equals the size of the Modulus (part of the key), so: 2048 bit Modulus -> 2048 bit output 1024 bit Modulus -> 1024 bit output ... If it is not, there exist numerous attacks on RSA , see here for basic information about that. So to guarantee that the output is 2048 bit even when the input to encrypt is, let's say 7 , a padding must always be applied! The output (as integer) of

Can we encrypt large files with ECC or it is like RSA works for small only? can anyone please recommend a good website for ECC Java implementation. Thanks In general you are required to perform hybrid encryption with ECC. ECIES for instance is basically a key agreement followed by symmetric encryption. So you cannot directly encrypt anything with ECIES, which is the most common ECC method for encryption. Basically you should couple it to a symmetric cipher. This is actually the best scheme for RSA encryption as well, most of the time. As you can see you can use this directly as a Cipher using