Create a secure signals adapter

Important: Secure signals are in beta. This document is intended for select partners only. Don't distribute this document without Google's authorization.

Secure signals are encoded data a client device collects and shares with select bidders. This page guides you on collecting and sending secure signals to Google Ad Manager using the Interactive Media Ads (IMA) SDK.

Before you begin

Before continuing, ensure you have the IMA SDK for iOS v3.18.5 or higher.

Create the secure signal adapter interface

To collect and provide secure signals, create classes that implement the interface:

Objective-C

• MySecureSignalsAdapter.h:

#import <Foundation/Foundation.h>
#import <GoogleInteractiveMediaAds/GoogleInteractiveMediaAds.h>
/** An example implementation of Secure Signals adapter. */
@interface MySecureSignalsAdapter : NSObject <IMASecureSignalsAdapter>
@end

• MySecureSignalsAdapter.m:

@implementation MySecureSignalsAdapter

  /**
* Default constructor with no arguments for IMA SDK to instantiate this class.
*/
- (instancetype)init {
  self = [super init];

  return self;
}
@end

Swift

import Foundation
import GoogleInteractiveMediaAds

/** An example implementation of Secure Signals adapter. */
@objc(MySecureSignalsAdapter)
public class MySecureSignalsAdapter: IMASecureSignalsAdapter {
  /**
  * Default constructor with no arguments for IMA SDK to instantiate this class.
  */
  override init() {
    super.init()
  }
}

Initialize the adapter

The IMA SDK initializes each adapter once by calling the initialization method of the adapter. Implement this method to begin any encryption dependencies, set up caches, or pre-calculating any signals that remain the same in all signal collection calls.

The following example initializes the adapter:

Objective-C

...
@interface MySecureSignalsAdapter
@property(nonatomic) NSError *initError;
@end
...
/**
* Initialize your SDK and any dependencies.
* IMA SDK calls this function exactly once before signal collection.
*/
- (instancetype)init {
  self = [super init];
  @try {
    // Initialize your SDK and any dependencies.
    ...
  }
  @catch(NSException *exception) {
    // Build NSError to be passed by Signal Collector.
    _initError = ...;
  }
  return self;
}
...

Swift

...
@objc(MySecureSignalsAdapter)
public class MySecureSignalsAdapter: IMASecureSignalsAdapter {
...
  private var initError

  override init() {
    super.init()

    do {
      // Initialize your SDK and any dependencies.
      ...
    } catch {
      // Build NSError to be passed by Signal Collector.
      self.initError = ...;
    }
  }
}

Signal collection

Before an ad request initiates, the IMA SDK calls a collect signals method asynchronously. These signal collector methods contain a callback function to pass the encrypted signals or report an error.

Note: Within 500 milliseconds, you must complete the signal collection, encryption, and pass the encrypted signal to the callback function. After 500 milliseconds, the IMA SDK discards any signal collection.

The following examples collect the secure signals through the callback function:

Objective-C

...
/**
* Invokes your SDK to collect, encrypt and pass the signal collection results to IMA SDK.
* IMA SDK calls this function before each ad request.
*
* @param completion A callback function to pass signal collection results to IMA SDK.
*/
- (void)collectSignalsWithCompletion:(IMASignalCompletionHandler)completion {
  // Output any initialization errors
  if (self.initError) {
    completion(nil, self.initError);
    return;
  }
  @try {
    // Collect and encrypt the signals.
    NSString *signals = ...
    // Pass the encrypted signals to IMA SDK.
    completion(signals, nil);
  }
  @catch(NSException *exception) {
    NSError *collectSignalError = ...;
    // Pass signal collection failures to IMA SDK.
    completion(nil, collectSignalError);
  }
}
...

Swift

...
  /**
  * Invokes your SDK to collect, encrypt and pass the signal collection results to IMA SDK.
  * IMA SDK calls this function before each ad request.
  *
  * @param completion A callback function to pass signal collection results to IMA SDK.
  */
  public func collectSignals(completion: @escaping IMASignalCompletionHandler) {
    if (self.initError) {
      completion(nil, self.initError)
      return
    }

    do {
      // Collect and encrypt the signals.
      var signals = ...
      // Pass the encrypted signals to IMA SDK.
      completion(signals, nil)
    } catch {
      NSError collectSignalError = ...
      // Pass signal collection failures to IMA SDK.
      completion(nil, collectSignalError)
    }
  }
...

Report errors

To communicate with users who use your adapter class, report all errors during the signal collection and pass them to the signal collector callback. This process troubleshoots issues that occur during integration of your adapter to applications.

Errors that might appear are as follows:

• Your SDK or a dependency is not found in the application.
• Your SDK or a dependency doesn't have the required permission or user consent to work.

Specify the adapter version

In your workflow, ensure you specify the version of the adapter. The IMA SDK includes your adapter version in each ad request and passes them with the secure signals in a bid request.

In the bid request, based on the adapter version, you can identify the encryption, encoding, and formatting details the adapter uses to create the secure signals.

The following example specifies the adapter version:

Objective-C

...
/**
* Specifies this adapter's version.
*/
static NSInteger const VersionMajor = 1;
static NSInteger const VersionMinor = 0;
static NSInteger const VersionPatch = 1;
...
/**
* @return The version of this adapter.
*         IMA SDK calls this function before each ad request.
*/
+ (IMAVersion *)adapterVersion {
  // The version of the SecureSignals Adapter.
  IMAVersion *adapterVersion = [[IMAVersion alloc] init];
  adapterVersion.majorVersion = VersionMajor;
  adapterVersion.minorVersion = VersionMinor;
  adapterVersion.patchVersion = VersionPatch;
  return adapterVersion;
}
...

Swift

...
  /**
  * Specifies this adapter's version.
  */
  static let VersionMajor = 1;
  static let VersionMinor = 0;
  static let VersionPatch = 1;
...
  /**
  * @return The version of this adapter.
  *         IMA SDK calls this function before each ad request.
  */
  public static func adapterVersion() -> IMAVersion {
    let adapterVersion = IMAVersion()
    adapterVersion.majorVersion = self.VersionMajor
    adapterVersion.minorVersion = self.VersionMinor
    adapterVersion.patchVersion = self.VersionPatch
    return adapterVersion
  }
...

Return the SDK runtime version

You can design your adapter to work with multiple versions of your SDK. For the adapter to work with multiple versions, ensure you return the runtime version of the SDK. In each ad request, the IMA SDK includes the runtime version with the adapter version.

The following examples requests and returns the SDK runtime version:

Objective-C

...
/**
* @return The version of your SDK that this adapter is depending on.
*         IMA SDK calls this function before each ad request.
*/
+ (IMAVersion *)adSDKVersion {
  // Request the version from your SDK and convert to an IMAVersion.
  int mySDKVersion[3] = ...

  IMAVersion *adSDKVersion = [[IMAVersion alloc] init];
  adSDKVersion.majorVersion = mySDKVersion[0];
  adSDKVersion.minorVersion = mySDKVersion[1];
  adSDKVersion.patchVersion = mySDKVersion[2];

  return adSDKVersion;
}
...

Swift

...
  /**
  * @return The version of your SDK that this adapter is depending on.
  *         IMA SDK calls this function before each ad request.
  */
public static func adSDKVersion() -> IMAVersion {
    // Request the version from your SDK and convert to an IMAVersion.
    let mySDKVersion = ...

    let adSDKVersion = IMAVersion()
    adSDKVersion.majorVersion = mySDKVersion[0]
    adSDKVersion.minorVersion = mySDKVersion[1]
    adSDKVersion.patchVersion = mySDKVersion[2]
    return adSDKVersion
  }
...

Register the adapter with Google

For Google to authorize the adapter for signal collection, you must register the iOS class name with Google. The IMA SDK initializes only those adapters you register with Google.

Validate the adapter

To validate the adapter, complete the following sections:

Configure the test application

Before you validate the adapter, configure the test application. Complete the following steps:

1. Add IMA SDK to your pod file:

   source 'https://github.com/CocoaPods/Specs.git'
   platform :ios, '10'
   target "BasicExample" do
     pod 'GoogleAds-IMA-iOS-SDK', '~> 3.17.0'
   end
   

2. Install IMA SDK using CocoaPods. For instructions on installing IMA SDK through CocoaPods, see Get started.

3. In your XCode project, add your adapter, SDK, and any remaining build dependencies you added.

Verify the signals

To verify the length of the secure signal, the encrypted value, your adapter version; and your SDK version, contact support to share the captured traffic log.

Review the complete examples

This section captures the completed example of all steps and available for your reference.

Objective-C

• MySecureSignalsAdapter.h:

#import <Foundation/Foundation.h>
#import <GoogleInteractiveMediaAds/GoogleInteractiveMediaAds.h>

/** An example implementation of Secure Signals adapter. */
@interface MySecureSignalsAdapter : NSObject <IMASecureSignalsAdapter>
@end

• MySecureSignalsAdapter.m:

#import "path/to/MyExampleSecureSignalsAdapter.h"

@interface MySecureSignalsAdapter
@property(nonatomic) NSError *initError;
@end

static NSInteger const VersionMajor = 1;
static NSInteger const VersionMinor = 0;
static NSInteger const VersionPatch = 1;

@implementation MySecureSignalsAdapter
/**
* Initialize your SDK and any dependencies.
* IMA SDK calls this function exactly once before signal collection.
*/
- (instancetype)init {
  self = [super init];
  @try {
    // Initialize your SDK and any dependencies.
    ...
  }
  @catch(NSException *exception) {
    // Build NSError to be passed by Signal Collector.
    _initError = ...;
  }
  return self;
}
/**
* Invokes your SDK to collect, encrypt and pass the signal collection results to IMA SDK.
* IMA SDK calls this function before each ad request.
*
* @param completion A callback function to pass signal collection results to IMA SDK.
*/
- (void)collectSignalsWithCompletion:(IMASignalCompletionHandler)completion {
  if (self.initError) {
    completion(nil, self.initError);
    return;
  }
  @try {
    // Collect and encrypt the signals.
    NSString *signals = ...
    // Pass the encrypted signals to IMA SDK.
    completion(signals, nil);
  }
  @catch(NSException *exception) {
    NSError *collectSignalError = ...;
    // Pass signal collection failures to IMA SDK.
    completion(nil, collectSignalError);
  }
}
/**
* @return The version of this adapter.
*         IMA SDK calls this function before each ad request.
*/
+ (IMAVersion *)adapterVersion {
  // The version of the SecureSignals Adapter.
  IMAVersion *adapterVersion = [[IMAVersion alloc] init];
  adapterVersion.majorVersion = VersionMajor;
  adapterVersion.minorVersion = VersionMinor;
  adapterVersion.patchVersion = VersionPatch;
  return adapterVersion;
}

/**
  * @return The version of your SDK that this adapter depends on.
  *         IMA SDK calls this function before each ad request.
  */
+ (IMAVersion *)adSDKVersion {
  // Request the version from your SDK and convert to an IMAVersion.
  int mySDKVersion[3] = ...

  IMAVersion *adSDKVersion = [[IMAVersion alloc] init];
  adSDKVersion.majorVersion = mySDKVersion[0];
  adSDKVersion.minorVersion = mySDKVersion[1];
  adSDKVersion.patchVersion = mySDKVersion[2];

  return adSDKVersion;
}

@end

Swift

@objc(MySecureSignalsAdapter)
public class MySecureSignalsAdapter: IMASecureSignalsAdapter {
  static let VersionMajor = 1;
  static let VersionMinor = 0;
  static let VersionPatch = 1;

  private var initError

  override init() {
    super.init()

    do {
      // Initialize your SDK and any dependencies.
      ...
    } catch {
      // Build NSError to be passed by Signal Collector.
      self.initError = ...;
    }
  }

  public func collectSignals(completion: @escaping IMASignalCompletionHandler) {
    if (self.initError) {
      completion(nil, self.initError)
      return
    }

    do {
      // Collect and encrypt the signals.
      var signals = ...
      // Pass the encrypted signals to IMA SDK.
      completion(signals, nil)
    } catch {
      NSError collectSignalError = ...
      // Pass signal collection failures to IMA SDK.
      completion(nil, collectSignalError)
    }      
  }

  public static func adapterVersion() -> IMAVersion {
    let adapterVersion = IMAVersion()
    adapterVersion.majorVersion = self.VersionMajor
    adapterVersion.minorVersion = self.VersionMinor
    adapterVersion.patchVersion = self.VersionPatch
    return adapterVersion
  }

  public static func adSDKVersion() -> IMAVersion {
    // Request the version from your SDK and convert to an IMAVersion.
    let mySDKVersion = ...

    let adSDKVersion = IMAVersion()
    adSDKVersion.majorVersion = mySDKVersion[0]
    adSDKVersion.minorVersion = mySDKVersion[1]
    adSDKVersion.patchVersion = mySDKVersion[2]
    return adSDKVersion
  }
}