This type of encryption uses a single key known as private key or secret key to encrypt and decrypt sensitive information. Here is an article where I have discussed about AES encryption in Java. Generating RSA Public Private Key. We can use factory method to generate these keys using KeyPairGenerator. For the demo purpose we are using a key. Keys can be used for Data Encryption and Digital Signing. They can be generated by OpenSSL which i have talked about in a previous article. OpenSSL – Generate a RSA Key and Keystore Actually, the Java JDK also provides API for creating key pair.
Generating Rsa Key And Signing Java Download
In this example you will sign the data contained in a file. GenSig gets the file name from the command line. A digital signature is created (or verified) using an instance of the Signature class. Signing data, generating a digital signature for that data, is done with the following steps.
Now that you have generated a signature for some data, you need to save the signature bytes in one file and the public key bytes in another so you can send (via modem, floppy, mail, and so on) someone else
Rsa Java Example
- the data for which the signature was generated,
- the signature, and
- the public key
Rsa Java Code
The receiver can verify that the data came from you and was not modified in transit by running the
VerSig
program you will generate in the upcoming Verifying a Digital Signature steps. That program uses the public key to verify that the signature received is the true signature for the data received.Recall that the signature was placed in a byte array named
realSig
. You can save the signature bytes in a file named sig
via the following.Recall from the Generate Public and Private Keys step that the public key was placed in a PublicKey object named
pub
. You can get the encoded key bytes by calling the getEncoded
method and then store the encoded bytes in a file. You can name the file whatever you want. If, for example, your name is Susan, you might name it something like suepk
(for 'Sue's public key'), as in the following:This lesson walks you through the steps necessary to use the JDK Security API to generate a digital signature for data and to verify that a signature is authentic. This lesson is meant for developers who wish to incorporate security functionality into their programs, including cryptography services.
This lesson demonstrates the use of the JDK Security API with respect to signing documents. The lesson shows what one program, executed by the person who has the original document, would do to generate keys, generate a digital signature for the document using the private key, and export the public key and the signature to files.
Then it shows an example of another program, executed by the receiver of the document, signature, and public key. It shows how the program could import the public key and verify the authenticity of the signature. The lesson also discusses and demonstrates possible alternative approaches and methods of supplying and importing keys, including in certificates.
For further information about the concepts and terminology (digital signatures, certificates, keystores), see the API and Tools Use for Secure Code and File Exchanges lesson.
In this lesson you create two basic applications, one for the digital signature generation and the other for the verification. This is followed by a discussion and demonstration of potential enhancements. The lesson contains three sections.
![Rsa Rsa](https://i.ytimg.com/vi/GDL3sbjOyTc/hqdefault.jpg)
- Generating a Digital Signature shows using the API to generate keys and a digital signature for data using the private key and to export the public key and the signature to files. The application gets the data file name from the command line.
- Verifying a Digital Signature shows using the API to import a public key and a signature that is alleged to be the signature of a specified data file and to verify the authenticity of the signature. The data, public key, and signature file names are specified on the command line.
- Weaknesses and Alternatives discusses potential weaknesses of the approach used by the basic programs. It then presents and demonstrates possible alternative approaches and methods of supplying and importing keys, including the use of files containing encoded key bytes and the use of certificates containing public keys.