Cloud Cryptography

Despite the convenience of cloud computing, there are still underlying problems that need to be pointed out. One such problem is security, you can not entrust your data with a cloud provider, in this modern world data is all it takes for a business to take off or. Therefore, protection methods should be applied to ensure that your data will be safe in the cloud. One of which is encryption. 

1. Definition:

Encryption is the process of converting information or data into a code to prevent unauthorized access. The act of employing an encryption method in the cloud is called cryptography. This allows users to safely and conveniently access shared cloud services without worrying about leaking out information as data is protected with encryption.

2. Type of cryptographic techniques:

Public-key cryptography, so-called asymmetric cryptography is encryption that uses a pair of keys for encrypting and decrypt, one public key and one private key. The public key is used to encrypt and the private key is used to decrypt. You can not predict the private key based on the public key therefore the public keys can be publicly shared. However, the only person who can decrypt the is the one holding the private key also the owner of the data.

Symmetric-key cryptography: While asymmetric encryption used a pair of keys, one public, and one private to encrypt and decrypt messages, symmetric-key cryptography used only one key for both encrypt and decrypt electronic information. Using this method, data is converted to a code that cannot be understood by anyone without the key to decrypt. There are two types of symmetric encryption algorithms:

- Block algorithms: with the use of a specific secret key set lengths of bits are encrypted in blocks of electronics. The system holds the data in its memory as it waits for complete blocks.

- Stream algorithms: Data is encrypted as it streams instead of being retained in the system’s memory.

Hash functions mathematical functions that convert a numerical input value into another compressed numerical value. The input is arbitrary length but the output is fixed length. Instead of the password itself, the enciphered text can be saved and later used to validate the user.

3. Real-life application of cryptography:

Authentication/Digital Signatures:

- Authentication is the process of proving and verifying certain information. Examples of information that need to be verified include the origin of a document, the identity of the sender, time and date a document was sent or signed, computer, or user identity. 

- The Digital Signature of a particular document is a piece of information based on both the document and the signer’s private key. Typically created through the use of a hash function and a private signing function.

Time Stamping: another real-life application of cryptography is time stamping. Timestamping is the technique that can certify a certain electronic document or communication that existed or was delivered at a certain time. A blind signature scheme model was used. This model allows the sender to get a message received by another party without publishing any information about the message to the other party.

Electronic Money (electronic cash or digital cash): This involves transfers carried out electronically with a net transfer from one party to another of funds that can be either debit or credit and can be either anonymous or identified.

Secure network communications: 

- Netscape's Secure Socket Layer ( SSL) is a public-key between TCP/IP (the cornerstone of Internet-based communication) and protocols (HTTP, Telnet, NNTP, or FPT) that provides data protection layers.

- Kerberos is an MIT-designed authentication service that uses secret-key encryption and authentication ciphers. It was designed to authenticate network resource requests and does not authenticate document authorship.

Anonymous remailers: it is a kind of service that strips off the header of information and only shows the content. However, to protect your own privacy, you shouldn’t entrust the operator entirely. Instead, you can relay a message through several anonymous remailers before sending it to the intended recipient.

Disk Encryption: Your whole hard drive will be encrypted by the program. In this way, you do not need to worry about leaving unencrypted data traces on the disk anymore.