gistfile1.txt

//Create contract resolver to handle the sensitive data, ignored properties etc.

public class CustomContractResolver : CamelCasePropertyNamesContractResolver
{
    private static readonly string[] ExcludedProperties =
    {
        "email", "password", "currentpassword", "newpassword", "token", "key
    };

    private static readonly string[] IgnoredProperties =
    {
        "file", "stream"
    };

    public static readonly CustomContractResolver Instance = new CustomContractResolver();

    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
    {
        var property = base.CreateProperty(member, memberSerialization);

        if (IgnoredProperties.Contains(property.PropertyName.ToLowerInvariant()))
        {
            property.Ignored = true;

            return property;
        }

        if (ExcludedProperties.Contains(property.PropertyName.ToLowerInvariant()))
        {
            return new JsonProperty
            {
                PropertyName = property.PropertyName,
                ValueProvider = CustomValueProvider.Instance,
                PropertyType = property.PropertyType,
                Readable = property.Readable
            };
        }

        return property;
    }
}


//Create value provider to encrypt/decrypt the data

public class CustomValueProvider : IValueProvider
{
    private const string DefaultValue = "*****";
    internal static readonly CustomValueProvider Instance = new CustomValueProvider();

    public void SetValue(object target, object value)
    {
    }

    public object GetValue(object target) => DefaultValue;
}


//Initialize contract resolver

var settings = new JsonSerializerSettings
{
    ContractResolver = new CustomContractResolver(),
};


//Use new settings to serialize/deserialize object

return JsonConvert.SerializeObject(value, settings);