The technology behind EMV emulation is neutral; the intent defines its morality.
For payment engineers, physically pressing and printing test cards is expensive and time-consuming. EMV emulators allow developers to:
While simple in logic, the cryptographic portion (RSA key generation and TDES MACing) is computationally heavy, requiring hardware acceleration in physical emulators.
The interaction between a card and a terminal is a complex dance of data exchange governed by the ISO/IEC 7816 standard. An emulator must master this dance.