The NFC Data Exchange Format (NDEF) is a standardized format for storing 
formatted data on NFC (Near Field Communication) tags and for transporting 
data across a peer-to-peer NFC link. Through NDEF and its various record 
types, events can be triggered on an NFC device by simply touching an 
NFC-enabled object. The number of use cases and real applications around NFC 
and NDEF technology increases continuously. However, existing applications 
provide hardly any protection against (malicious) manipulation of NDEF data. 
Digital signatures are a means of providing authenticity and integrity of 
NDEF data. Therefore, the NFC Forum -- which is responsible for the 
specification of data formats, protocols and applications in regard to the 
NFC technology -- is working on adding digital signatures to their NDEF 
format. While their signature record type is still in draft status and has 
not been released to the public, this paper discusses the various aspects of 
digitally signing NDEF records. First, we introduce the readers to the NFC 
Data Exchange Format, its use cases and its potential security threats. After 
that, we describe the potential of digital signatures for NDEF messages. 
Finally, we discuss the advantages and disadvantages of various ways to 
digitally sign an NDEF message.