The issue of key distribution is complex, involving cryptographic protocol and management considerations. This guide will provide you with a feel for the issues involved in Key Distribution and Management. We all also survey the aspects of Key Management and Distribution.
Afreen and Anjali want to form a relationship. The message can be any confidential thing. Any other third person says Ishaani wants to know what’s going on between Afreen and Anjali. She is a smart girl who is a threat to their confidential messages.
Do you know how things work over the internet.? Let’s say Afreen wants to send a document to Anjali. There are many computers and networks between the sender and the receiver. That’s where Ishaani comes in.
The most common encryption is symmetric encryption. It has a single key. You can encrypt plaintext to ciphertext thought this key. As well as decrypt ciphertext back into plaintext using the same key.
One way of sharing the key is to meet and discuss their secrets and come up with a key. Then they can encrypt and decrypt with the key they agreed upon in a meeting.
However, remember that if Afreen and Anjali live far away from each other such that meeting is not possible. and it is entirely possible that there is a situation where it is dangerous to share a key. And the alternative for Afreen is to generate a key and send it to Anjali. Perhaps though the post or perhaps over the internet.
But you cannot 100% trust courier services. If Ishaani really wants to know the key, she can steal it from services by hook or crook.
You can give the key to armed guard to deliver but you can imagine how much-armed guards are expensive. Only governments and very largest companies can afford armed guards for key distribution.
You see we have many problems in sharing the key physically. Now you will see the same problems we face on the internet as well.
You may like to send the key through email, Facebook or WhatsApp or whatever another possible way. But you might be aware of internet phishing and hacking. Hacker can steal your key. This problem is named as the key distribution problem.
The proper solution
Before the 1970s, people believed that there is no solution to this problem. Asymmetric encryption is the solution. It has two keys. The first key is called the public key which encrypts plaintext to ciphertext. The second key is the secret key which decrypts ciphertext back to plaintext.
For symmetric cryptography, the two parties must share the same key, and that key must be protected from others accessing it.
In asymmetric cryptography, the users public key needs to be distributed to other users. And the public key needs to be bound with the correct user.
The key distribution and Management that achieves such features is one of the most critical areas in system security
On many occasions, the systems have been broken not because of the poor encryption algorithm, but because of the poor key selection or management. It is very important in cryptography and computer security, in general, to distribute and manage keys in a secret and secure manner.
Afreen and Anjali establish:
– The shared secret key for symmetric cryptocurrency
– Valid/Authenticated public keys for the asymmetric cryptocurrency.
The strength of any cryptographic system, therefore, often depends on the key distribution technique.
For two parties A and B, the key distribution can be achieved in several ways. One approach is for user A to physically deliver the key to user B, and another, the second approach, is having a third party, physically deliver the key to both users A and B.
Physical delivery works well, but it requires physical contact or connection between the nodes which can significantly limit the application of such approaches, based on physical delivery. These approaches are also more appropriate for the link encryption where the devices and the keys occur in pairs, but they do not scale well as several parties who wish to communicate what grows and increases.
Another approach is to use the previous keys to encrypt the new key. This approach assumes prior communications between user A and B. It also suffers that if an attacker succeeds in gaining access to one key, then all the subsequent keys are compromised, and so are the corresponding communications.
Another approach is to use the third party who is trusted by A and B, by both. This third party can be used as the trusted intermediary to mediate the secure key distribution between user A and user B. This approach can be used to build a practical solution with larger networks supporting the growth and number of keys potentially needed.