I think my class become more interesting now, when we going to learn deeper on cryptography method and techniques been using from past years ago until to newest techniques to suite the current technology.
So what is cryptography really about? Like this. Every of us must have a secret, and some have more than others. But when it becomes necessary to transmit those secrets from one point to another, it’s important to protect the information while it's in transit.
Cryptography presents various methods for taking legible, readable data, and transforming it into unreadable data for the purpose of secure transmission, and then using a key to transform it back into readable data when it reaches its destination, so only the right person get the authority to read that data or message.
Cryptography is the science of keeping data secure. It is a discipline which concerned with communication security such as confidentiality of messages, integrity of messages, sender authentication, regardless of the used medium such as pencil and paper or computers.
Cryptographic algorithms
- Secret Key Cryptography (SKC): Uses a single key for both encryption and decryption
- Public Key Cryptography (PKC): Uses one key for encryption and another for decryption
- Hash Functions: Uses a mathematical transformation to irreversibly "encrypt" information
Secret Key Cryptography
With secret key cryptography, a single key is used for both encryption and decryption. Refer to figure i attached at the end of the post, the sender uses the key (or some set of rules) to encrypt the plaintext and sends the ciphertext to the receiver. The receiver applies the same key (or ruleset) to decrypt the message and recover the plaintext. Because a single key is used for both functions, secret key cryptography is also called symmetric encryption.
Secret key cryptography algorithms that are in use today include:
With secret key cryptography, a single key is used for both encryption and decryption. Refer to figure i attached at the end of the post, the sender uses the key (or some set of rules) to encrypt the plaintext and sends the ciphertext to the receiver. The receiver applies the same key (or ruleset) to decrypt the message and recover the plaintext. Because a single key is used for both functions, secret key cryptography is also called symmetric encryption.
Secret key cryptography algorithms that are in use today include:
- Data Encryption Standard (DES)
- Advanced Encryption Standard (AES)
- CAST-128/256
- International Data Encryption Algorithm (IDEA)
- Rivest Ciphers (aka Ron's Code)
- Blowfish
- Twofish
- Camellia
- MISTY
- KASUMI
- SEED
- Skipjack
Public Key Cryptography
Public-key cryptography has been said to be the most significant new development in cryptography in the last 300-400 years. Modern PKC was first described publicly by Stanford University professor Martin Hellman and graduate student Whitfield Diffie in 1976. Their paper described a two-key crypto system in which two parties could engage in a secure communication over a non-secure communications channel without having to share a secret key.
Public-key cryptography algorithms that are in use today for key exchange or digital signatures include:
Public-key cryptography has been said to be the most significant new development in cryptography in the last 300-400 years. Modern PKC was first described publicly by Stanford University professor Martin Hellman and graduate student Whitfield Diffie in 1976. Their paper described a two-key crypto system in which two parties could engage in a secure communication over a non-secure communications channel without having to share a secret key.
Public-key cryptography algorithms that are in use today for key exchange or digital signatures include:
- RSA
- Diffie-Hellman
- Digital Signature Algorithm (DSA)
- ElGamal
- Elliptic Curve Cryptography (ECC)
- Cramer-Shoup
- Key Exchange Algorithm (KEA)
- LUC: Can be used for encryption and signatures, using integer factoring.
Hash Functions
Hash functions, also called message digests and one-way encryption, are algorithms that, in some sense, use no key (Figure 1C). Instead, a fixed-length hash value is computed based upon the plaintext that makes it impossible for either the contents or length of the plaintext to be recovered. Hash algorithms are typically used to provide a digital fingerprint of a file's contents, often used to ensure that the file has not been altered by an intruder or virus. Hash functions are also commonly employed by many operating systems to encrypt passwords. Hash functions, then, provide a measure of the integrity of a file.
Hash algorithms that are in common use today include:
Hash functions, also called message digests and one-way encryption, are algorithms that, in some sense, use no key (Figure 1C). Instead, a fixed-length hash value is computed based upon the plaintext that makes it impossible for either the contents or length of the plaintext to be recovered. Hash algorithms are typically used to provide a digital fingerprint of a file's contents, often used to ensure that the file has not been altered by an intruder or virus. Hash functions are also commonly employed by many operating systems to encrypt passwords. Hash functions, then, provide a measure of the integrity of a file.
Hash algorithms that are in common use today include:
- Message Digest (MD) algorithms
- Secure Hash Algorithm (SHA)
- HAVAL (HAsh of VAriable Length)
- Whirlpool
- Tiger
So, i guess this figure can help you to understand the text!
