string serverCommonName = serverCert.GetNameInfo(X509NameType.SimpleName, false);
var endpointAddress = new EndpointAddress(new Uri(serviceAddress), EndpointIdentity.CreateDnsIdentity(serverCommonName));

<identity>
                    <dns value="localhost" />
                </identity>

        public SMEVClient(string portName)
        {
            if (string.IsNullOrEmpty(portName))
            {
                throw new ArgumentException("Не задано имя конечной точки.");
            }

            // Создаем фабрику каналов
            var factory = new ChannelFactory<IService>(portName);

            string serverCommonName = factory.Credentials.ServiceCertificate.DefaultCertificate.GetNameInfo(X509NameType.SimpleName, false);
            var endpointAddress = new EndpointAddress(factory.Endpoint.Address.Uri, EndpointIdentity.CreateDnsIdentity(serverCommonName));
            factory.Endpoint.Address = endpointAddress;
            factory.Endpoint.Contract.ProtectionLevel = ProtectionLevel.Sign;

            // Создаем канал к сервису
            dbDataChannel = factory.CreateChannel();
        }