hi thanks for your responseHave you read it?
please do suggest me any other methods to convert the public key into bigintegerErr, no, you haven't read it. The public key is composed of two numbers. (x,y) You can convert each of those to a BigInteger. You can't convert the key itself to a BigInteger, because it isn't a number. It is two numbers. I already said that.
for converting the private key into biginteger i used these code..That code converts one of the numbers comprising the private key to a BigInteger. It isn't useful without the other nunber, and it doesn't constitute 'convert[ing] the private key to a BigInteger'.
BigInteger s = ((ECPrivateKey) privKey).getS();
by using XOR operation (x,y)values can be converted into single valueCertainly, but the process loses information so you cannot recover the key from that number.