Editing Chosen-plaintext attack (section)

{{short description|Attack model for cryptanalysis with presumed access to ciphertexts for chosen plaintexts}}
{{Refimprove|date=November 2015}}
A '''chosen-plaintext attack''' ('''CPA''') is an [[attack model]] for [[cryptanalysis]] which presumes that the attacker can obtain the [[ciphertext]]s for arbitrary [[plaintext]]s.<ref name="RASE">Ross Anderson, ''Security Engineering: A Guide to Building Dependable Distributed Systems''. The first edition (2001): http://www.cl.cam.ac.uk/~rja14/book.html</ref> The goal of the attack is to gain information that reduces the security of the [[encryption]] scheme.<ref>{{Cite journal|last1=Barrera|first1=John Fredy|last2=Vargas|first2=Carlos|last3=Tebaldi|first3=Myrian|last4=Torroba|first4=Roberto|date=2010-10-15|title=Chosen-plaintext attack on a joint transform correlator encrypting system|url=https://www.sciencedirect.com/science/article/pii/S0030401810006036|journal=Optics Communications|language=en|volume=283|issue=20|pages=3917–3921|doi=10.1016/j.optcom.2010.06.009|bibcode=2010OptCo.283.3917B|issn=0030-4018|url-access=subscription}}</ref>

Modern ciphers aim to provide semantic security, also known as ''ciphertext indistinguishability under chosen-plaintext attack'', and they are therefore, by design, generally immune to chosen-plaintext attacks if correctly implemented.