net.rim.device.api.crypto
Class ECDHKeyAgreement

java.lang.Object
  net.rim.device.api.crypto.ECDHKeyAgreement

public final class ECDHKeyAgreement
extends Object

Implements the elliptic curve analog of the Diffie-Hellman algorithm.

Elliptic Curve cryptography is defined in various standards including P1363 and ANSI X9.62.

Category:

Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.

Since:

BlackBerry API 3.6.0

Method Summary
	static byte[]	generateSharedSecret(ECPrivateKey localPrivateKey, ECPublicKey remotePublicKey, boolean useCofactor) Generates the shared secret for elliptic curve Diffie-Hellman key agreement using a given public key (from another party) and a private key with the option of the cofactor of the elliptic curve being used in the shared secret calculations.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

generateSharedSecret

public static byte[] generateSharedSecret(ECPrivateKey localPrivateKey,
                                          ECPublicKey remotePublicKey,
                                          boolean useCofactor)
                                   throws InvalidCryptoSystemException,
                                          CryptoTokenException,
                                          CryptoUnsupportedOperationException

Generates the shared secret for elliptic curve Diffie-Hellman key agreement using a given public key (from another party) and a private key with the option of the cofactor of the elliptic curve being used in the shared secret calculations. The cofactor is used to prevent small subgroup attacks. Note that using the cofactor is the defacto standard for elliptic curve operations.

Parameters:

localPrivateKey - The local private key to use.

remotePublicKey - The remote public key to use.

useCofactor - If true, the cofactor of the elliptic curve is used in the calculations. If false, it is not used. Note, setting this value to TRUE is the most common usage.

Returns:

A byte array containing the shared secret data. Note that the value returned is the raw shared secret, which technically is an element of the finite field that the elliptic curve is defined over. The caller can then take this byte array and feed it into any PseudoRandomSource to create a symmetric key, etc.

Throws:

InvalidCryptoSystemException - Thrown if the local crypto system is different than the remote crypto system

CryptoTokenException - Thrown if an error occurs with the crypto token or the crypto token is invalid.

CryptoUnsupportedOperationException - Thrown if a call is made to an unsupported operation.

Category:

Signed: This element is only accessible by signed applications. If you intend to use this element, please visit http://www.blackberry.com/go/codesigning to obtain a set of code signing keys. Code signing is only required for applications running on BlackBerry smartphones; development on BlackBerry Smartphone Simulators can occur without code signing.

Since:

BlackBerry API 3.6.0