Proofreading fixes 0x05d part 1

Document/0x05d-Testing-Data-Storage.md

@@ -2,27 +2,27 @@
 
 Protecting authentication tokens, private information, and other sensitive data is key to mobile security. In this chapter, you will learn about the APIs Android offers for local data storage and best practices for using them.
 
-The guidelines for saving data can be summarized quite easily: Public data should be available to everyone, but sensitive and private data must be protected, or, better yet, kept out of device storage.
+The guidelines for saving data can be summarized quite easily: public data should be available to everyone, but sensitive and private data must be protected, or, better yet, kept out of device storage.
 
-This chapter is broken into two sections, the first of which focuses on the theory of data storage from a security perspective as well as a brief explanation and example of the various methods of data storage on Android.
+This chapter is broken into two sections, the first of which focuses on the theory of data storage from a security perspective as well as a brief explanation and some examples of the various methods of data storage on Android.
 
 The second section focuses on the testing of these data storage solutions through the usage of test cases that utilize both static and dynamic analysis.
 
 ## Theory Overview
 
-[Storing data](https://developer.android.com/guide/topics/data/data-storage.html "Storing Data in Android") is essential to many mobile apps. Conventional wisdom suggests that as little sensitive data as possible should be stored on permanent local storage. In most practical scenarios, however, some type of user data must be stored. For example, asking the user to enter a very complex password every time the app starts isn't a great idea in terms of usability. Most apps must locally cache some kind of authentication token to avoid this. Personally identifiable information (PII) and other types of sensitive data may also be saved if a given scenario calls for it.
+[Storing data](https://developer.android.com/training/data-storage "Storing Data in Android") is essential to many mobile apps. Conventional wisdom suggests that as little sensitive data as possible should be stored on permanent local storage. In most practical scenarios, however, some type of user data must be stored. For example, asking the user to enter a very complex password every time the app starts isn't a great idea in terms of usability. Most apps must locally cache some kind of authentication token to avoid this. Personally identifiable information (PII) and other types of sensitive data may also be saved if a given scenario calls for it.
 
 Sensitive data is vulnerable when it is not properly protected by the app that is persistently storing it. The app may be able to store the data in several places, for example, on the device or on an external SD card. When you're trying to exploit these kinds of issues, consider that a lot of information may be processed and stored in different locations.
 
 First, it is important to identify the kind of information processed by the mobile application and input by the user. Next, determining what can be considered sensitive data that may be valuable to attackers (e.g., passwords, credit card information, PII) is not always a trivial task and it strongly depends on the context of the target application. You can find more details regarding data classification in the "[Identifying Sensitive Data](0x04b-Mobile-App-Security-Testing.md#identifying-sensitive-data "Identifying Sensitive Data")" section of the chapter "Mobile App Security Testing". For general information on Android Data Storage Security, refer to the [Security Tips for Storing Data](https://developer.android.com/training/articles/security-tips.html#StoringData "Security Tips for Storing Data") in the Android developer's guide.
 
 Disclosing sensitive information has several consequences, including decrypted information. In general, an attacker may identify this information and use it for additional attacks, such as social engineering (if PII has been disclosed), account hijacking (if session information or an authentication token has been disclosed), and gathering information from apps that have a payment option (to attack and abuse them).
 
-Next to protecting sensitive data, you need to ensure that data read from any storage source is validated and possibly sanitized. The validation usually ranges from checking for the correct data types to using additional cryptographic controls, such as an HMAC, you can validate the integrity of the data.
+Next to protecting sensitive data, you need to ensure that data read from any storage source is validated and possibly sanitized. The validation usually ranges from checking for the correct data types to using additional cryptographic controls, such as an HMAC that allows you to validate the integrity of the data.
 
 ## Data Storage Methods Overview
 
-Android provides a number of methods for [data storage](https://developer.android.com/guide/topics/data/data-storage.html "Storing Data in Android") depending on the needs of the user, developer, and application. For example, some apps use data storage to keep track of user settings or user-provided data. Data can be stored persistently for this use case in several ways. The following list of persistent storage techniques are widely used on the Android platform:
+Android provides a number of methods for [data storage](https://developer.android.com/training/data-storage "Storing Data in Android") depending on the needs of the user, developer, and application. For example, some apps use data storage to keep track of user settings or user-provided data. Data can be stored persistently for this use case in several ways. The following list of persistent storage techniques are widely used on the Android platform:
 
 - Shared Preferences
 - SQLite Databases