Cryptography is the science of using mathematics to encrypt and decrypt data. Cryptography is the study of secure communication that allows the sender and recipient of a message to have highly secure and confidential to view its contents. The data is encrypted using a secret key, and then both the encoded message and secret key are sent to the recipient for decryption. In simple words the art of writing or solving codes is cryptography. Cryptography can be classified into there types:
-> Symmetric Key Cryptography: With symmetric cryptography, the same key is used for both encryption and decryption. A sender and a recipient must already have a shared key that is known to both. This system of cryptography is faster but both parties must exchange their key in a secured way. The most common and popular example of symmetric key cryptography is Data Encryption System(DES)
-> Asymmetric Key Cryptography: Here, two different keys are used for encryption and decryption. Every user in an asymmetric cryptography system has both a public key and a private key. The public key is used for encryption and may be distributed but private key is used for decryption and must be confidential. One can decode with a private key only. Digital Signature Standard (DSS) is one of the popular Asymmetric Key Cryptography.
-> Hashing cryptography: It converts any form of data into a unique string of text. Hashing is a mathematical operation that is easy to perform, but immense hard to reverse. MD5, SHA1, etc are popular hash functions used widely for hashing.
The major goals/objectives of cryptography that uplift the standard and present itself as a most trusted mode of communication is C.I.A, i.e. Confidentiality, Integrity, Authenticity.
- Confidentiality:- Sender encrypts the message with a cryptographic key and recipient decrypts it using a cryptographic key. Hence confidentiality ensures that only recipient can access and read the content.
- Integrity:- Integrity ensures that the information in the message cannot be modified, i.e. received message is the same message sent. It is mostly used in digital signatures to protect against unauthorized or malicious alteration. Here hash functions are used to create unique string for every character.
- Authenticity:- Here sender and recipient can approve or verity each other identity and destination of message. Kerberos is a common cryptographic authentication system.
Hence it is very true that cryptography is very secure and can protect confidential information that traverses various untrusted networks. The confidentiality and integrity protections offered by cryptographic protocols such as SSL/TLS can protect information and contents from malicious unauthorized eavesdropping and tampering.
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