8). CHAP 6 - ASYMMETRIC KEY ALGORITHMS: (a.k.a. PUBLIC KEY).....

D1). Asymmetric Key Cryptography Weakness:

Its slow speed of operation. For this reason, many applications that require the secure transmission of large amounts of data use public key cryptography to establish a connection and then exchange a symmetric secret key.

C2). Removing users:

Provide a KEY REVOCATION MECHANISM that allows a key to be canceled, effectively removing a user from the system.

C0. Major Strengths Of Asymmetric Cryptography:

The following is a list of the major strengths of asymmetric key cryptography:

B2. ((n*(n-1))÷2)

Key Requirements - 5, multiplied by 5 - 1 = (4), "5*4=20", 20 ÷ 2 = "10" 10 Keys.

C5). Asymmetric Key Encryption Supports -

Of the FOUR FUNDAMENTAL CRYPTOGRAPHIC GOALS: 1). Confidentiality, 2). Integrity, 3). Authentication, and 4). Nonrepudiation Symmetric Key Cryptography supports: 2). Integrity, 3). Authentication & 4) Nonrepudiation!

A4. Asymmetric 2). RECEIVE/DECRYPT:

The receiver "Bob" decrypts the delivered ciphertext using their private key, and the only user with access to that key is "Bob". Therefore, "Alice" (the sender) can't even decrypt the message herself after she encrypts it.

A3. Asymmetric 1). ENCRYPT/SEND:

The sender "Alice" creates the message and then encrypts it using the receivers "Bob" public key.

C1). Adding new users:

The addition of new users requires the generation of only one public-private key pair.

C6). Key Distribution:

Users who want to participate in the system simply make their public key available to anyone with whom they want to communicate. There is no method by which the private key can be derived from the public key.

A6. Nonrepudiation:

Asymmetric key algorithms also provide support for digital signature technology. Basically, if Bob wants to assure other users that a message with his name on it was actually sent by him.

A2. Asymmetric Key Algorithms:

Asymmetric key algorithms, also known as public key algorithms, provide a solution to the weaknesses of symmetric key encryption. In these systems, each user has two keys: a public key, which is shared with all users, and a private key, which is kept secret and known only to the user. But here's a twist: opposite and related keys must be used in tandem to encrypt and decrypt. In other words, if the public key encrypts a message, then only the corresponding private key can decrypt it, and vice versa. Figure 6.4 shows the algorithm used to encrypt and decrypt messages in a public key cryptosystem. Consider this example. If Alice wants to send a message to Bob using public key cryptography, she creates the message and then encrypts it using Bob's public key. The only possible way to decrypt this ciphertext is to use Bob's private key, and the only user with access to that key is Bob. Therefore, Alice can't even decrypt the message herself after she encrypts it. If Bob wants to send a reply to Alice, he simply encrypts the message using Alice's public key, and then Alice reads the message by decrypting it with her private key. Each user has two keys: 1). A PUBLIC KEY, which is shared with all users, and a 2). PRIVATE KEY, which is kept secret and known only to the user. Opposite and related keys must be used in tandem to encrypt and decrypt. In other words, if 1). the PUBLIC key ENCRYPTS a MESSAGE, then only 2). the CORRESPONDING PRIVATE key can DECRYPT IT, and vice versa.

A5. Asymmetric 3). ENCRYPT/REPLY/SEND:

If the receiver "Bob" wants to send a reply to the sender "Alice", he simply encrypts the message using the senders "Alice's" public key.

C7). Sharing Keys:

No preexisting communication link needs to exist. Two individuals can begin communicating securely from the moment they start communicating. Does not require a preexisting relationship to provide a secure mechanism for data exchange.

C3). Key Regeneration:

Only required only when a user's private key is compromised AND ONLY FOR THAT USER. If a user leaves the community, the system administrator simply needs to invalidate that user's keys. No other keys are compromised and therefore key regeneration is not required for any other user.