func Example_decryptMessage() {
	pkBytes, err := hex.DecodeString("a11b0a4e1a132305652ee7a8eb7848f6ad" +
		"5ea381e3ce20a2c086a2e388230811")
	if err != nil {
		fmt.Println(err)
		return
	}
	privKey, _ := btcec.PrivKeyFromBytes(btcec.S256(), pkBytes)
	ciphertext, err := hex.DecodeString("35f644fbfb208bc71e57684c3c8b437402ca" +
		"002047a2f1b38aa1a8f1d5121778378414f708fe13ebf7b4a7bb74407288c1958969" +
		"00207cf4ac6057406e40f79961c973309a892732ae7a74ee96cd89823913b8b8d650" +
		"a44166dc61ea1c419d47077b748a9c06b8d57af72deb2819d98a9d503efc59fc8307" +
		"d14174f8b83354fac3ff56075162")
	plaintext, err := btcec.Decrypt(privKey, ciphertext)
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Println(string(plaintext))
}
This example demonstrates decrypting a message using a private key that is
first parsed from raw bytes.
package btcec_test
import (
	"encoding/hex"
	"fmt"
	"github.com/btcsuite/btcd/btcec"
	"github.com/btcsuite/btcd/chaincfg/chainhash"
)
func Example_signMessage() {
	pkBytes, err := hex.DecodeString("22a47fa09a223f2aa079edf85a7c2d4f87" +
		"20ee63e502ee2869afab7de234b80c")
	if err != nil {
		fmt.Println(err)
		return
	}
	privKey, pubKey := btcec.PrivKeyFromBytes(btcec.S256(), pkBytes)
	message := "test message"
	messageHash := chainhash.DoubleHashB([]byte(message))
	signature, err := privKey.Sign(messageHash)
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Printf("Serialized Signature: %x\n", signature.Serialize())
	verified := signature.Verify(messageHash, pubKey)
	fmt.Printf("Signature Verified? %v\n", verified)
}
func Example_verifySignature() {
	pubKeyBytes, err := hex.DecodeString("02a673638cb9587cb68ea08dbef685c" +
		"6f2d2a751a8b3c6f2a7e9a4999e6e4bfaf5")
	if err != nil {
		fmt.Println(err)
		return
	}
	pubKey, err := btcec.ParsePubKey(pubKeyBytes, btcec.S256())
	if err != nil {
		fmt.Println(err)
		return
	}
	sigBytes, err := hex.DecodeString("30450220090ebfb3690a0ff115bb1b38b" +
		"8b323a667b7653454f1bccb06d4bbdca42c2079022100ec95778b51e707" +
		"1cb1205f8bde9af6592fc978b0452dafe599481c46d6b2e479")
	if err != nil {
		fmt.Println(err)
		return
	}
	signature, err := btcec.ParseSignature(sigBytes, btcec.S256())
	if err != nil {
		fmt.Println(err)
		return
	}
	message := "test message"
	messageHash := chainhash.DoubleHashB([]byte(message))
	verified := signature.Verify(messageHash, pubKey)
	fmt.Println("Signature Verified?", verified)
}
func Example_encryptMessage() {
	pubKeyBytes, err := hex.DecodeString("04115c42e757b2efb7671c578530ec191a1" +
		"359381e6a71127a9d37c486fd30dae57e76dc58f693bd7e7010358ce6b165e483a29" +
		"21010db67ac11b1b51b651953d2")  
	if err != nil {
		fmt.Println(err)
		return
	}
	pubKey, err := btcec.ParsePubKey(pubKeyBytes, btcec.S256())
	if err != nil {
		fmt.Println(err)
		return
	}
	message := "test message"
	ciphertext, err := btcec.Encrypt(pubKey, []byte(message))
	if err != nil {
		fmt.Println(err)
		return
	}
	pkBytes, err := hex.DecodeString("a11b0a4e1a132305652ee7a8eb7848f6ad" +
		"5ea381e3ce20a2c086a2e388230811")
	if err != nil {
		fmt.Println(err)
		return
	}
	privKey, _ := btcec.PrivKeyFromBytes(btcec.S256(), pkBytes)
	plaintext, err := btcec.Decrypt(privKey, ciphertext)
	if err != nil {
		fmt.Println(err)
		return
	}
	fmt.Println(string(plaintext))
}