SCA

SCA stands for Strong Customer Authentication in the context of the Payment Services Directive 2 (PSD2).

(30) ‘strong customer authentication’ means an authentication based on the use of two or more elements categorised as knowledge (something only the user knows), possession (something only the user possesses) and inherence (something the user is) that are independent, in that the breach of one does not compromise the reliability of the others, and is designed in such a way as to protect the confidentiality of the authentication data.