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# TKSmartCardATR.InterfaceGroup

A single interface-bytes group for a Smart Card ATR (Answer to Reset).

```
class InterfaceGroup
```

## Overview

You access instances of this class by calling the [`interfaceGroup(at:)`](/documentation/CryptoTokenKit/TKSmartCardATR/interfaceGroup(at:)) and [`interfaceGroup(for:)`](/documentation/CryptoTokenKit/TKSmartCardATR/interfaceGroup(for:)) methods on an [`TKSmartCardATR`](/documentation/CryptoTokenKit/TKSmartCardATR) object.

## Topics

### Accessing Interface Group Protocol and Bytes

[`protocol`](/documentation/CryptoTokenKit/TKSmartCardATR/InterfaceGroup/protocol)

The protocol for this group.

[`ta`](/documentation/CryptoTokenKit/TKSmartCardATR/InterfaceGroup/ta)

The TA interface byte of ATR group, or `nil` if TA is not present.

[`tb`](/documentation/CryptoTokenKit/TKSmartCardATR/InterfaceGroup/tb)

The TB interface byte of ATR group, or `nil` if TB is not present.

[`tc`](/documentation/CryptoTokenKit/TKSmartCardATR/InterfaceGroup/tc)

The TC interface byte of ATR group, or `nil` if TC is not present.


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