Definitions – “Digital signature” – Anweshon.com || Prepare Yourself for Future

And a “Digital signature” is impossible to forge. Instead, the digital signature comes from a digest of the text encrypted and sent with the text message.

The recipient decrypts the signature and retrieves the digest from the received text.

A match authenticates the message. Digital signatures are required for open systems and need higher security levels. An electronic signature that authenticates the identity of the sender, ensures the original content of the message is unchanged, is easily transportable, cannot be easily repudiated, cannot be imitated, and can be automatically time-stamped.

Digital signatures are often used to implement electronic signatures, a broader term that refers to any electronic data that carries the intent of a signature, but not all electronic signatures use digital signatures. An electronic signature is “a computer data compilation of any symbol or series of symbols executed, adopted, or authorized by an individual to be the legally binding equivalent of the individual’s handwritten signature.”

They are the electronic equivalent to handwritten signatures on paper and may be based on biometric identification methods or facial and voice recognition. A simple combination of a user ID and password also is sufficient. Within a company, the user ID must be unique to a specific person.

Password – The use of a user name and password provide the most common form of authentication. You enter your name and password when prompted by the computer. It checks the pair against a secure file to confirm. If either the name or password do not match, then you are not allowed further access.

Checksum – Probably one of the oldest methods of ensuring that data is correct, checksums also provide a form of authentication since an invalid checksum suggests that the data has been compromised in some fashion. A checksum is determined in one of two ways. Let’s say the checksum of a packet is 1 byte long, which means it can have a maximum value of 255. If the sum of the other bytes in the packet is 255 or less, then the checksum contains that exact value. However, if the sum of the other bytes is more than 255, then the checksum is the remainder of the total value after it has been divided by 256. Look at this example:

Private key encryption

Private key means that each computer has a secret key (code) that it can use to encrypt a packet of information before it is sent over the network to the other computer. Private key requires that you know which computers will talk to each other and install the key on each one. Private key encryption is essentially the same as a secret code that the two computers must each know in order to decode the information. The code would provide the key to decoding the message. Think of it like this. You create a coded message to send to a friend where each letter is substituted by the letter that is second from it. So “A” becomes “C” and “B” becomes “D”. You have already told a trusted friend that the code is “Shift by 2″. Your friend gets the message and decodes it. Anyone else who sees the message will only see nonsense.

Public key encryption –

Public key encryption uses a combination of a private key and a public key. The private key is known only to your computer while the public key is given by your computer to any computer that wants to communicate securely with it. To decode an encrypted message, a computer must use the public key provided by the originating computer and it’s own private key. The key is based on a hash value. This is a value that is computed from a base input number using a hashing algorithm. The important thing about a hash value is that it is nearly impossible to derive the original input number without knowing the data used to create the hash value.

Major types of digital forensics are as follows

Database Forensics – which helps in checking databases for information
Network Forensics – used for the understanding of data flow in networks to prevent issues and find out what happened
Mobile Forensics- this will help to get information from phones or tablets to solve cases
Malware Forensics – which is used for harmful computer viruses to know who made them and what it will cause
Email Forensics – using emails to check out its source from whom it is sent and confirming the date and contents of the mail
Memory Forensics – used for checking hidden memories or information from the computers