Customer identity specialist Signal has launched a system that spans online and offline channels. Signal captures identity information from multiple sources and builds a list of identifiers for each person. Personal identifiers such as email addresses are hashed (i.e., converted to a unique but anonymized form) so they can be used for matching without being exposed. Clients can load some customer attributes but Signal doesn’t build a database of detailed customer information. Connectors let client systems call Signal to identify visitors at any touchpoint. Signal started as BrightTag, a tag management solution.