Encryption is the process of encoding messages or information in such a way that only authorized parties can read it. Encryption has long been used by militaries and governments to facilitate secret communication. It is now commonly used in protecting information within many kinds of civilian systems.
3 different encryption methods
There are three different basic encryption methods, each with their own advantages :
Hashing creates a unique, fixed-length signature for a message or data set. Each “hash” is unique to a specific message, so minor changes to that message would be easy to track. Once data is encrypted using hashing, it cannot be reversed or deciphered. Hashing, then, though not technically an encryption method as such, is still useful for proving data hasn’t been tampered with.
2. Symmetric methods
Symmetric encryption is also known as private-key cryptography, and is called so because the key used to encrypt and decrypt the message must remain secure, because anyone with access to it can decrypt the data. Using this method, a sender encrypts the data with one key, sends the data (the ciphertext) and then the receiver uses the key to decrypt the data.
Symmetric encryption or private key encryption
3. Asymmetric methods
Asymmetric encryption, or public-key cryptography, is different than the previous method because it uses two keys for encryption or decryption (it has the potential to be more secure as such). With this method, a public key is freely available to everyone and is used to encrypt messages, and a different, private key is used by the recipient to decrypt messages.
Asymmetric method or public-key encryption
Different Encryption Standards
There are of course a wide range of cryptographic algorithms in use. The following are amongst the most well known:
- DES – This is the ‘Data Encryption Standard’. This is a cipher that operates on 64-bit blocks of data, using a 56-bit key. It is a ‘private key’ system. The Data Encryption Standard is a previously predominant symmetric-key algorithm for the encryption of electronic data. It was highly influential in the advancement of modern cryptography in the academic world.
- RSA – RSA is one of the first practicable public-key cryptosystems and is widely used for secure data transmission.RSA involves a public key and a private key. The public key can be known by everyone and is used for encrypting messages. Messages encrypted with the public key can only be decrypted in a reasonable amount of time using the private key.
- HASH – A ‘hash algorithm’ is used for computing a condensed representation of a fixed length message/file. This is sometimes known as a ‘message digest’, or a ‘fingerprint’.
- MD5 – MD5 is a 128 bit message digest function. The MD5 message-digest algorithm is a widely used cryptographic hash function producing a 128-bit (16-byte) hash value, typically expressed in text format as a 32 digit hexadecimal number. MD5 has been utilized in a wide variety of cryptographic applications, and is also commonly used to verify data integrity.
- AES – This is the Advanced Encryption Standard (using the Rijndael block cipher) approved by NIST. Advanced Encryption Standard uses a symmetric 128-bit block data encryption technique . The U.S government adopted the algorithm as its encryption technique in October 2000, replacing the DES encryption it used. AES works at multiple network layers simultaneously. It is considered one of the most secure forms of encryption in modern world.
- SHA-1 – SHA-1 is a hashing algorithm similar in structure to MD5, but producing a digest of 160 bits (20 bytes).Because of the large digest size, it is less likely that two different messages will have the same SHA-1 message digest. For this reason SHA-1 is recommended in preference to MD5.
- HMAC – HMAC is a hashing method that uses a key in conjunction with an algorithm such as MD5 or SHA-1. Thus one can refer to HMAC-MD5 and HMAC-SHA1.