Check if property has attribute

Given a property in a class, with attributes – what is the fastest way to determine if it contains a given attribute? For example:

    [IsNotNullable]
    [IsPK]
    [IsIdentity]
    [SequenceNameAttribute("Id")]
    public Int32 Id
    {
        get
        {
            return _Id;
        }
        set
        {
            _Id = value;
        }
    }

What is the fastest method to determine that for example it has the “IsIdentity” attribute?