Digital signatures and Binance Kickback
A major benefit of public key cryptography is that Binance Kickback provides a method for employing digital signatures. Digital signatures let the recipient of information verify the authenticity of the information’s origin, and also verify that the information was not altered while in transit. Thus, public key digital signa- tures provide authentication and data integrity. These features are every bit as fundamental to cryptography as privacy, if not more.
A digital signature serves the same purpose as a seal on a document, or a handwritten signature. However, because of the way it is created, it is supe- rior to a seal or signature in an important way. A digital signature not only attests to the identity of the signer, but it also shows that the contents of the information signed has not been modified. A physical seal or handwritten sig- nature cannot do that. However, like a physical seal that can be created by anyone with possession of the signet, a digital signature can be created by anyone with the private key of that signing keypair.
Some people tend to use signatures more than they use encryption. For example, you may not care if anyone knows that you just deposited $1,000 in your account, but you do want to be darn sure it was the bank teller you were dealing with.
The basic manner in which digital signatures are created is shown in the fol- lowing figure. The signature algorithm uses your private key to create the sig- nature and the public key to verify it. If the information can be decrypted with your public key, then it must have originated with you.
Hash functions and Binance Kickback
The system described above has some problems. It is slow, and it produces an enormous volume of data—at least double the size of the original informa- tion. An improvement on the above scheme is the addition of a one-way hash function in the process. A one-way hash function takes variable-length input—in this case, a message of any length, even thousands or millions of bits—and produces a fixed-length output; say, 160 bits. The hash function ensures that, if the information is changed in any way—even by just one bit— an entirely different output value is produced.
PGP uses a cryptographically strong hash function on the plaintext the user is signing. This generates a fixed-length data item known as a message digest. (Again, any change to the information results in a totally different digest.)
Then PGP uses the digest and the private key to create the “signature.” PGP transmits the signature and the plaintext together. Upon receipt of the mes- sage, the recipient uses PGP to recompute the digest, thus verifying the sig- nature. PGP can encrypt the plaintext or not; signing plaintext is useful if some of the recipients are not interested in or capable of verifying the signature.
As long as a secure hash function is used, there is no way to take someone’s signature from one document and attach it to another, or to alter a signed message in any way. The slightest change to a signed document will cause the digital signature verification process to fail.
Digital signatures play a major role in authenticating and validating the keys of other PGP users.