interaction attribute name checksum rigid PSI-MI 2014-01-09T11:17:32Z A global unique identifier to identify interactions that are identical. A RIG identifier (RIGID) is constructed by concatenating ROGID MI:1335 (after sorting them in ascending lexicographical order ), applying the SHA-1 algorithm to the resulting string, converting the digest to its base64 representation and removing all trailing "=" characters used for padding. orchard MI:1334