PublicWalletService.cryptoService.deriveKey(this.password, (err,key) => {
 if(err){
   return callback(err,null);
 }
 var serialized = Serialize(this.walletInfo);
 var stringified = JSON.stringify(serialized);
 let encrypted = PublicWalletService.cryptoService.encrypt(key, stringified);
 return callback(null, encrypted);
 });

 (err,results) => {
   if(err){
     return callback(err,null);
   }
   var serialized = Serialize(this.walletInfo);
   var stringified = JSON.stringify(serialized);
   let encrypted = PrivateWalletService.cryptoService.encrypt(results['cryptoKey'], stringified);
   return callback(null, encrypted);
 });

	/** Saves modifications of the given user. */
	save(user: User): Observable<User> {
		const body = JSON.stringify(Serialize(user));
		const headers = new Headers({ 'Content-Type': 'application/json' });
		const options = new RequestOptions({ headers: headers });
		const url = `${API_URL}/${user._key}`;
		return this.http.patch(url, body, options)
			.map((res: Response) => {
				const updated = Deserialize(res.json(), User);
				return updated;
			});
	}

	/** Adds the given member into the party. */
	addMember(party: Party, office: Office, user: User, location: Location): Observable<Member> {
		user = _.pick(user, '_key') as User;
		location = _.pick(location, '_key') as Location;
		const member = new Member(user, office, location);
		const body = JSON.stringify(Serialize(member));
		const options = this.defaultOptions();
		return this.http.post(`${API_URL}/${party._key}/member`, body, options)
		.map(response => {
			const added = Deserialize(response.json(), Member);
			return added;
		});
	}

	/** Saves the given political party. */
	save(party: Party): Observable<Party> {
		const body = JSON.stringify(Serialize(party));
		const options = this.defaultOptions();
		const stream = party._rev ?
			this.http.patch(`${API_URL}/${party._key}`, body, options) :
			this.http.post(API_URL, body, options);

		return stream.map(response => {
			const saved = Deserialize(response.json(), Party);
			return saved;
		});
	}

	/** Saves (insert/update) the given answer. */
	saveAnswer(answer: Answer): Observable<Answer> {
		const body = JSON.stringify(Serialize(answer));
		const options = this.defaultOptions();
		const stream = answer._rev ?
			this.http.patch(`${ANSWER_URL}/${answer._key}`, body, options) :
			this.http.post(`${ANSWER_URL}/${answer.question._key}`, body, options);

		return stream.map(response => {
			const saved = Deserialize(response.json(), Answer);
			return saved;
		});
	}

	/** Saves (insert/update) the given question. */
	save(question: Question): Observable<Question> {
		const body = JSON.stringify(Serialize(question));
		const options = this.defaultOptions();
		const stream = question._rev ?
			this.http.patch(`${QUESTION_URL}/${question._key}`, body, options) :
			this.http.post(QUESTION_URL, body, options);

		return stream.map(response => {
			const saved = Deserialize(response.json(), Question);
			return saved;
		});
	}