Public Key Private Key Generation Java
Below is the relevant information from the link which Zaki provided. Generate a 2048-bit RSA private key $ openssl genrsa -out privatekey.pem 2048. Convert private Key to PKCS#8 format (so Java can read it). The whole point of public-key cryptography is that the private key remains secret. If there would be a way to easily generate a private key from a public key the encryption schema would be broken. Yes, you can probably brute-force the private key but it won't be easy.
- Public Key Private Key Generation Java Key
- Private Key Bitcoin
- Private Key Definition
- Public Key Private Key Generation Java Free
When using this curve and generating your public key, -you- have to choose your private key randomly, in a way that it is impossible for anyone to guess it. The generateor G is a specific point on the elliptic curve, defined in the secp256k1 curve.
The KeyPairGenerator class is used to generate pairs of public and private keys. Key pair generators are constructed using thegetInstance
factory methods (static methods that return instances of a given class). A Key pair generator for a particular algorithm creates a public/private key pair that can be used with this algorithm. It also associates algorithm-specific parameters with each of the generated keys.
Public Key Private Key Generation Java Key
There are two ways to generate a key pair: in an algorithm-independent manner, and in an algorithm-specific manner. The only difference between the two is the initialization of the object:
- Algorithm-Independent Initialization
All key pair generators share the concepts of a keysize and a source of randomness. The keysize is interpreted differently for different algorithms (e.g., in the case of the DSA algorithm, the keysize corresponds to the length of the modulus). There is an
initialize
method in this KeyPairGenerator class that takes these two universally shared types of arguments. There is also one that takes just akeysize
argument, and uses theSecureRandom
implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation ofSecureRandom
, a system-provided source of randomness is used.)Since no other parameters are specified when you call the above algorithm-independent
initialize
methods, it is up to the provider what to do about the algorithm-specific parameters (if any) to be associated with each of the keys.If the algorithm is the DSA algorithm, and the keysize (modulus size) is 512, 768, or 1024, then the Sun provider uses a set of precomputed values for the
p
,q
, andg
parameters. If the modulus size is not one of the above values, the Sun provider creates a new set of parameters. Other providers might have precomputed parameter sets for more than just the three modulus sizes mentioned above. Still others might not have a list of precomputed parameters at all and instead always create new parameter sets. - Algorithm-Specific Initialization
For situations where a set of algorithm-specific parameters already exists (e.g., so-called community parameters in DSA), there are two
initialize
methods that have anAlgorithmParameterSpec
argument. One also has aSecureRandom
argument, while the the other uses theSecureRandom
implementation of the highest-priority installed provider as the source of randomness. (If none of the installed providers supply an implementation ofSecureRandom
, a system-provided source of randomness is used.)
In case the client does not explicitly initialize the KeyPairGenerator (via a call to an initialize
method), each provider must supply (and document) a default initialization. For example, the Sun provider uses a default modulus size (keysize) of 1024 bits.
Note that this class is abstract and extends from KeyPairGeneratorSpi
for historical reasons. Application developers should only take notice of the methods defined in this KeyPairGenerator
class; all the methods in the superclass are intended for cryptographic service providers who wish to supply their own implementations of key pair generators.
Private Key Bitcoin
Every implementation of the Java platform is required to support the following standard KeyPairGenerator
algorithms and keysizes in parentheses:
Private Key Definition
DiffieHellman
(1024)DSA
(1024)RSA
(1024, 2048)