var rsaUtil = {
    bits: 1024,
    thisKeyPair: {},
    genKeyPair: function() {
    	bits = rsaUtil.bits
        var genKeyPair = {};
        rsaUtil.thisKeyPair = new JSEncrypt({default_key_size: bits});

        genKeyPair.privateKey = rsaUtil.thisKeyPair.getPrivateKey();

        genKeyPair.publicKey = rsaUtil.thisKeyPair.getPublicKey();

        return genKeyPair;
    },

    encrypt: function (plaintext, publicKey) {
        publicKey && rsaUtil.thisKeyPair.setPublicKey(publicKey);
        return rsaUtil.thisKeyPair.encrypt(plaintext);
    },

    // ˽Կ����
    decrypt: function (ciphertext, privateKey) {
        privateKey && rsaUtil.thisKeyPair.setPrivateKey(privateKey);
        return rsaUtil.thisKeyPair.decrypt(ciphertext);
    }
};