technews-editor@acm.org
Date: Fri, 17 Mar 2017 12:13:55 -0400 (EDT)
CORDIS News (16 Mar 2017) via ACM TechNews, 17 Mar 2017
Researchers in Poland and the Czech Republic have theoretically shown that ultrasecure currency designed using quantum mechanics can be forged by exploiting a serious security flaw. The quantum money was minted photonically, with a series of photons transmitted to a bank using their polarizations to encode information. Criminals intercepting the photons would find accurate counterfeiting impossible because duplicating quantum data is imperfect. However, because individual photons can be missed or distorted in transmission, banks accept partial quantum bills, which gives crooks an opening to make imperfect forgeries that are still similar enough for banks to verify them. Using an optimal cloner, the researchers demonstrated a bank would accept forged quantum currency if the standard for accuracy was not sufficiently high. They say an effective standard for acceptance would require the received photons' polarizations to be more than approximately 84-percent identical to the original. https://orange.hosting.lsoft.com/trk/click?ref=3Dznwrbbrs9_6-12fadx211524x072322&