A data encryption/decryption IC is a specialized integrated circuit (IC) that can encrypt outgoing data and decrypt incoming data. Some such devices are intended for half-duplex operation (in which input and output do not occur simultaneously), and others are designed for full-duplex operation (where input and output can occur simultaneously).
Encryption is the conversion of data into a form, called a cipher, that cannot be understood by unauthorized people. Decryption is the process of converting encrypted data back into its original form, so it can be understood. Encryption and decryption should not be confused with encoding and decoding, in which data is converted from one form to another but is not deliberately altered so as to conceal its content.
An integrated circuit, sometimes called a chip or microchip, is a semiconductor wafer on which thousands or millions of tiny resistors, capacitors, and transistors are fabricated. These devices can perform dozens of tasks in electronics and computing.