The main step for information security is to deploy the defined security policies efficiently and then keep every process under the defined policies. Although, in professional terms, there is no facilitation of 100% guaranteed security because there is always a loophole in a system and even there are few loopholes in the models that are defined for information security.
Some of the main components of information security include confidentiality, integrity and availability.

Confidentiality

Confidentiality is the protection of information from unauthorised users. To achieve confidentiality the information must need to be stored hidden or encrypted. A good example is a cryptography, which is traditionally used to protect secret messages. But cryptography is traditionally used to protect data, not resources. Resources are protected by limiting information, for example by using firewalls or address translation mechanisms.

Integrity

Integrity is basically to keep information protected from any modifications. In this case, modifications have several goals, such as ensure the information integrity with respect to the original information, ensure a source of data, and protect information from any incorrect modifications.
A good example is of an interrupted database transaction, leaving the database in an inconsistent state. The trustworthiness of both data and origin affects integrity.  Cryptography provides mechanisms for detecting violations of integrity, but not preventing them (e.g., a digital signature can be used to determine if data has been changed).

Availability

Availability ensures that authorised users are getting access to the information. This is usually defined in terms of “quality of service” in which authorised users are expected to receive a specific level of service. Denial of service (DOS) attack is an attempt to block availability.