Data Integrity

ISO 27001 makes use of a systematic management approach to help organizations:

• identify information security risks that can promise information confidentiality, integrity or availability (based on their context, objectives and interested parties needs)
• define proper controls to treat relevant risks (based on controls from Annex A, as well as from other sources of controls if needed), and expected information security performance results (i.e. information security objectives)
• periodically evaluate information security performance
• implement corrections and/or improvements based on achieved results

Regarding controls specifically related to protection of information integrity, these are some examples:

• A.10.1 Cryptographic controls
• A.12.5.1 Installation of software on operational systems
• A.9.4.4 Use of privileged utility programs 
• A.12.1.2 Change management

These articles will provide you further explanation about ISO 27001:

• The basic logic of ISO 27001: How does information security work? https://advisera.com/27001academy/knowledgebase/the-basic-logic-of-iso-27001-how-does-information-security-work/
•  Where to start from with ISO 27001 https://advisera.com/27001academy/knowledgebase/iso-27001-where-to-start-most-important-materials/

These materials will also help you regarding ISO 27001:

• Book Secure & Simple: A Small-Business Guide to Implementing ISO 27001 On Your Own https://advisera.com/books/secure-and-simple-a-small-business-guide-to-implementing-iso-27001-on-your-own/
• Free online training ISO 27001 Foundations Course https://advisera.com/training/iso-27001-foundations-course/