A communication device (100; 200; 300), comprising: a transponder unit (110; 210; 310) configured for at least one of sending data to and receiving data from another communication device; a biometric sensor unit (122; 226; 326) configured to sense biometric data of a user of the communication device (100; 200; 300); and a security interface unit (120; 220; 320) coupled to the transponder unit (110; 210; 310) and the biometric sensor unit (122; 226; 326), wherein the security interface unit (120; 220; 320) is configured to enable the transponder unit (110; 210; 310) for at least one of sending and receiving data upon biometric data sensed by the biometric sensor unit (122; 226; 326) being verified as representing verified biometric data, wherein the transponder unit (110; 210; 310) comprises a microcontroller (110c; 214; 322) and a communication interface (110a; 212; 312), wherein operation of the communication interface (110a; 212; 312) is disabled until the communication device (100; 200; 300) is unlocked by the biometric data sensed by the biometric sensor unit (122; 226; 326) being verified by the security interface unit (120; 220; 320) as representing verified biometric data, wherein only the transponder unit (110; 210; 310) is configured to be unlocked when the identity of the user is confirmed by means of the verified biometric data, wherein the security interface unit (120; 220; 320) is configured to compare sensed biometric data with verified biometric data stored in a memory of the communication device (100; 200; 300) and to issue an enabling signal to the communication interface (110a; 212; 312) of the transponder unit (110; 210; 310) for enabling at least one of sending data to and receiving data from the other communication device, and wherein the enabling signal is characterised by comprising a valid identification signal, and the communication device being further characterised by the microcontroller (110c; 214; 322) being configured to compare the valid identification signal with a plurality of verified valid identification signals and to output an activation signal to the communication interface (110a; 212; 312) on the basis of the enabling signal in case of encountering a match of the valid identification signal with a verified valid identification signal. a transponder unit (110; 210; 310) configured for at least one of sending data to and receiving data from another communication device; a biometric sensor unit (122; 226; 326) configured to sense biometric data of a user of the communication device (100; 200; 300); and a security interface unit (120; 220; 320) coupled to the transponder unit (110; 210; 310) and the biometric sensor unit (122; 226; 326), wherein the security interface unit (120; 220; 320) is configured to enable the transponder unit (110; 210; 310) for at least one of sending and receiving data upon biometric data sensed by the biometric sensor unit (122; 226; 326) being verified as representing verified biometric data, wherein the transponder unit (110; 210; 310) comprises a microcontroller (110c; 214; 322) and a communication interface (110a; 212; 312), wherein operation of the communication interface (110a; 212; 312) is disabled until the communication device (100; 200; 300) is unlocked by the biometric data sensed by the biometric sensor unit (122; 226; 326) being verified by the security interface unit (120; 220; 320) as representing verified biometric data, wherein only the transponder unit (110; 210; 310) is configured to be unlocked when the identity of the user is confirmed by means of the verified biometric data, wherein the security interface unit (120; 220; 320) is configured to compare sensed biometric data with verified biometric data stored in a memory of the communication device (100; 200; 300) and to issue an enabling signal to the communication interface (110a; 212; 312) of the transponder unit (110; 210; 310) for enabling at least one of sending data to and receiving data from the other communication device, and wherein the enabling signal is characterised by comprising a valid identification signal, and the communication device being further characterised by the microcontroller (110c; 214; 322) being configured to compare the valid identification signal with a plurality of verified valid identification signals and to output an activation signal to the communication interface (110a; 212; 312) on the basis of the enabling signal in case of encountering a match of the valid identification signal with a verified valid identification signal.