CONFIDENTIAL SORT SYSTEM AND METHOD

• Main Authors: CHIDA, Koji, HAMADA, Koki, IKARASHI, Dai
• Format: Patent
• Language: English; French; German
• Published: 19.08.2020
• Subjects: ADVERTISING; CODING OR CIPHERING APPARATUS FOR CRYPTOGRAPHIC OR OTHERPURPOSES INVOLVING THE NEED FOR SECRECY; CRYPTOGRAPHY; DISPLAY; EDUCATION; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PHYSICS; SEALS; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

The present invention provides a technique for performing confidential sort at a faster speed than in the prior art. A confidential sort system comprises first to Mth apparatuses. The first to Mth apparatuses obtain inverse substitution [[σ0-1]] of L-bit stable sort of {→k0}. The first to Mth apparatuses perform, on i=1,...,N-1, a process of converting [[σi-1-1]] to hybrid substitution to obtain {σi-1-1}, a process of inversely substituting {→ki} with {σi-1-1} to obtain {σi-1→ki}, a process of obtaining inverse substitution [[σi'-1]] of L-bit stable sort of [[σi-1→ki]], a process of synthesizing {σi-1-1} with [[σi'-1]] to obtain [[σi-1]]:=[[σi-1-1σi'-1]], and a process of converting [[σN-1-1]] to hybrid substitution to obtain {σN-1-1}. The first to Mth apparatuses inversely substitute [[→v]] with {σN-1-1} and output [[σN-1→v]].