{"id":20643,"date":"2020-09-17T10:26:20","date_gmt":"2020-09-17T04:56:20","guid":{"rendered":"https:\/\/www.mygreatlearning.com\/blog\/image-steganography-explained\/"},"modified":"2024-10-15T01:06:16","modified_gmt":"2024-10-14T19:36:16","slug":"image-steganography-explained","status":"publish","type":"post","link":"https:\/\/www.mygreatlearning.com\/blog\/image-steganography-explained\/","title":{"rendered":"Image Steganography Explained | What is Image Steganography?"},"content":{"rendered":"\n

Contributed by: Sendil A B <\/a><\/em><\/p>\n\n\n\n

What is Steganography?<\/strong><\/h2>\n\n\n\n

Steganography is the study and practice of concealing information within objects in such a way that it deceives the viewer as if there is no information hidden within the object. Simply put, it is hiding information in plain sight, such that only the intended recipient would get to see it. <\/p>\n\n\n\n

How is this different from cryptography?<\/strong><\/h2>\n\n\n\n

It may immediately occur to us that this is similar to cryptography, but it is not so. In cryptography, the objective is to modify the original message in such a fashion it becomes difficult to get to the original message from the modified message. The original and modified messages are explicitly expected to look different. While in image steganography, the objective is to deceptively hide a message within another original message and thereby, modifying it. The modified message is expected to look very similar to the original message. <\/p>\n\n\n\n

Let\u2019s consider a scenario where two employees are expected to exchange official messages via email. In this case, we know that they will exchange messages, and hence, there is no need for them to hide those messages. However, as those messages might contain sensitive information, they might want to encrypt-decrypt it using cryptography. On the contrary, consider information exchange between a spy, operating undercover in the opponents\u2019 military regiment and his parent organization, with whom he wants to share important information. In this case, the officers would be monitoring pretty much everything that goes in and out of his room. Hence, if he resorts to using cryptography to share encrypted information, officers might get suspicious. In such a situation, he might prefer image steganography, where he would deceptively hide a message within another object\/message, without raising suspicions, and find a way to drop it off to his recipient. In summary, cryptography hides the meaning of the data, while steganography hides the existence of the data<\/strong>. Although they are different techniques, they might as well be used in combination, in the same instance, to get the best of both worlds. <\/p>\n\n\n\n

Also Read: What is Image Recognition? How is it used? <\/a><\/p>\n\n\n\n

Incidents from history<\/strong><\/h2>\n\n\n\n

Steganography has been with us for ages, be it the spies in the Revolutionary War writing in invisible ink or Da Vinci embedding a secret meaning in a painting. Steganography traces its roots back to 500 BC. The first physical case of steganography is found in Histories by Herodotus, where he talks about the Greek leader Histiaeus' act.  Histiaeus was stuck in an enemy camp and was in dire need of sending a message to his camp. He then resorted to shaving a trusted slave\u2019s head, tattooing a secret message on his scalp, letting his hair grow, and then sending him off to be shaved again by the message\u2019s recipient<\/p>\n\n\n\n

On the other end of the timeline, steganography is also being used recently. It is expected to be in use in the forthcoming years. For example, it was used very recently to drop malware into user\u2019s computers, by sending them innocent-looking messages but hiding the malware within, using steganography techniques.<\/p>\n\n\n\n

Use cases or applications of steganography<\/strong><\/h2>\n\n\n\n

Although the prime objective is to share messages or information discreetly, it has found varied fields of applications such as <\/p>\n\n\n\n