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package java.security.interfaces;

import java.math.BigInteger;
import java.security.PublicKey;

An interface for an elliptic curve public key as defined by RFC 7748. These keys are distinct from the keys represented by ECPublicKey, and they are intended for use with algorithms based on RFC 7748 such as the XDH KeyAgreement algorithm. An XEC public key is a particular point on the curve, which is represented using only its u-coordinate as described in RFC 7748. A u-coordinate is an element of the field of integers modulo some value that is determined by the algorithm parameters. This field element is represented by a BigInteger which may hold any value. That is, the BigInteger is not restricted to the range of canonical field elements. 
Since:
11/**
 * An interface for an elliptic curve public key as defined by RFC 7748.
 * These keys are distinct from the keys represented by {@code ECPublicKey},
 * and they are intended for use with algorithms based on RFC 7748 such as the
 * XDH {@code KeyAgreement} algorithm.
 *
 * An XEC public key is a particular point on the curve, which is represented
 * using only its u-coordinate as described in RFC 7748. A u-coordinate is an
 * element of the field of integers modulo some value that is determined by
 * the algorithm parameters. This field element is represented by a BigInteger
 * which may hold any value. That is, the BigInteger is not restricted to the
 * range of canonical field elements.
 *
 * @since 11
 */
public interface XECPublicKey extends XECKey, PublicKey {

    
Get the u coordinate of the point.
Returns:
the u-coordinate, represented using a BigInteger which may hold
         any value/**
     * Get the u coordinate of the point.
     *
     * @return the u-coordinate, represented using a BigInteger which may hold
     *          any value
     */
    BigInteger getU();

}