Image replay attack?

 An image replay attack is the use of a picture to trick an authentication method.

Image replay attacks are most commonly used by an attacker trying to gain entry to a system protected by less secure biometric authentication. The method has been used successfully against common finger scanners, iris scanners, and facial recognition approaches.

Consider this real-world example of an attack. A staff member at a company asks for a financial transfer by sending an encrypted message to the company's financial officer. An attacker eavesdrops on this message, captures it, and is now in a position to resend it. Because it's an authentic message that has simply been resent, the message is already correctly encrypted and looks legitimate to the financial administrator.

In this method, the financial administrator is likely to respond to this new request unless he or she has a good reason to be doubtful. That response could include sending a large sum of money to the attacker's bank account.

Making biometric authentication methods secure from image replay attacks can't depend on the methods used to detect data replay attacks.

Preventing such an attack is all about having the right method of encryption. Encrypted messages carry keys within them, and when they're decoded at the end of the transmission, they open the message. In a replay attack, it doesn't matter if the attacker who precluded the original message can read or translate the key. All he or she has to do is grab and resend the whole thing message and key together.