Senior software developer
Like a signature, a digital signature allows to authenticate the emitter of the message and verify the message has not been modified since it has been signed. How does the digital signature work ?
A hash function takes any string as input and computes a fixed size fingerprint.
The hashes of two equal messages are equal. If the hashes of two strings are equal, it does not imply that the two strings are equal.
With the symmetric cryptography, a same password is used to encrypt and decrypt a message. The problem is how to safely exchange this password ? This password has to be exchanged in clear in internet and a third person will be able to intercept this…