Roles and Functions of Digital Signatures
The next section on this opportunity we will discuss about Digital Signature , or Digital Signature. Digital signatures are needed in the process of making blocks in digital currency.
Technically, this digital signature is like signing on paper in general. Only, this signature is done digitally, can be on a document, or a file.
There are two things that need to be done so that this digital signature can function like a handwritten signature on paper. First, this digital signature can only be done by yourself.However, others who can see it, will be able to verify its validity.
Second, affix this signature as a binder on a particular document. So it can not be used to indicate your approval or support on certain other documents.
Next, how can I make this digital signature in cryptography ? The digital signature scheme consists of the following three algorithms:
⦁ (sk, pk): = generateKeys (keysize)
This generateKeyys method serves to obtain the key size and also generate its key pair .While sk is a private key that is confidential and kept secret to sign a message. And, pk is a public key that can be given to others. With this key , others will be able to verify the digital signature.
For the record in this case, that the generateKeys and sign can be a random algorithm.Basically generateKeys would be better if scrambled. Because then it can create different keys for different people. On the other hand, always be deterministic, in accordance with its function.
⦁ sig: = sign (sk, message)
This method will take the key as well as the message (message) . Next, s k as input, to be able to produce the output of signature on message under sk .
⦁ isValid: = verify (pk, message, sig)
This way to retrieve messages, signatures, and public key as input. Then, make it a booleanvalue, which is true or false ( true or false ). Whereas isValid will return a true statement, if the sig in the message contains a valid signature, under public key ( pk ). Next, it will be false if it shows the opposite.
The three algorithms, should be able to meet two of the following:
⦁ A valid signature must be verified first.
verify ( pk , message, sign (sk, message)) == true
⦁ Signatures are existentially unforgeable .