Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for detecting network attacks. One of the methods includes obtaining input data associated with a plurality of accounts associated with a particular entity; extracting features from the input data; performing unsupervised attack ring detection using the extracted features, wherein the unsupervised attack ring detection identifies suspicious clusters of accounts that have strong similarity or correlations in the high dimensional feature space; and generating an output for the detected attack rings.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for detecting network attacks. One of the methods includes obtaining input data associated with a plurality of accounts associated with a particular entity; extracting features from the input data; performing unsupervised attack ring detection using the extracted features, wherein the unsupervised attack ring detection identifies suspicious clusters of accounts that have strong similarity or correlations in the high dimensional feature space; and generating an output for the detected attack rings.

Abstract: A diode string for a semiconductor circuit configured with a guard ring silicon-controlled rectifier (SCR) for electrostatic discharge (ESD) protection. The diode string includes multiple NPN transistor diode structures formed in an N-well structure and electrically coupled in series between a reference voltage node and an I/O pad. Each diode structure may include a P-type retro-well structure including at least one N+ doped region and at least one P+ doped region. The P+ guard ring includes at least one P+ doped structure formed in the N-well structure disposed on either side of the first diode structure and electrically coupled to the reference voltage node. The P+ guard ring forms the SCR with the first diode structure. The diode string is triggered in response to an ESD event, which activates the SCR, and the SCR clamps the I/O pad to the reference voltage node and handles the ESD current.