Based Encryption (ABE) was the first type proposed by Sahai and Waters. It is a
type of public key encryption in which secret key of the user depends upon the
attributes like country , state , area etc . It was mainly used for log
Based Encryption (IBE) is a type of public key encryption proposed by Adil
Shamir . In this type of encryption the key depends upon the identity of a
particular user like his pet name or something . This identity is only known to
the user .
Policy attribute based encryption (KP ABE) also have the one to many
communication technique . In this encryption user can generate a secret key by
picking out the key policy given to him by the servers . There can be only one
domain for each user . KP ABE is one of the type of attribute based encryption
Policy Attribute Based Encryption (CP ABE) is the other type of attribute based
encryption in which the key is associated with the attributes and ciphertext
specifies the access policy in order to encrypt the data . A user can decrypt the
data if and only if his attributes satisfies the given policy .
Hierarchy Ciphertext Policy Attribute Based Encryption (FH CP ABE) is the
advance technique in which the hierarcal structure of files is being showed .
Generally other ABE does not have a well defined structure for the hierarchy structure
of the shared files . This is technique is still in process and going to be
updated very soon . This can provide a greater use for the security in the
field of cloud computing .
Apart from these techniques there
were multiple attempts to secure the file in the cloud by saving the time and
cost of encryption . There were many challenges as well while proposing all
these techniques . these all concepts are mainly based upon the public key
cryptography which helps a user encrypt the data .