New Release 350-701 CCNP Security Questions

ExplanationA data breach is the intentional or unintentional release of secure or private/confidential information to anuntrusted environment.When your credentials have been compromised, it means someone other than you may be in possession of your account information, such as your username and/or password.

The best way to prevent the session during the initial TCP communication is to configure policies to stop and reject communication from the known malicious domain. This will prevent the ESA from accepting any messages from that domain and send a negative SMTP response code back to the sender. This will also save the ESA’s resources and bandwidth, as it will not have to process or store the malicious emails. This can be done by creating a sender group in the Host Access Table (HAT) that matches the malicious domain and setting the mail flow policy to “Reject” or “Throttle”. Alternatively, a message filter can be created that checks the envelope sender against the malicious domain and applies the “stop_connection” or “reject_connection” action12.

The other options are not as effective as stopping and rejecting the communication at the TCP level. Configuring the Cisco ESA to drop the malicious emails (option A) will still allow the ESA to accept the messages and then silently discard them, which will consume the ESA’s resources and bandwidth, and also not notify the sender of the rejection. Configuring policies to quarantine malicious emails (option B) will also require the ESA to accept and store the messages, which will take up disk space and require manual or automated management of the quarantine. Configuring the Cisco ESA to reset the TCP connection (option D) will abruptly terminate the connection without sending a proper SMTP response code, which may cause the sender to retry the delivery and generate more traffic. Resetting the TCP connection is also considered a less polite and less compliant way of rejecting messages than sending a negative SMTP response code34. References: 1: How to Block a Sender Domain on the Email Security Appliance 2: Message Filters on the Cisco Email Security Appliance 3: How to Configure the Cisco Email Security Appliance to Reject or Drop Messages 4: Cisco Email Security Appliance User Guide - Configuring Mail Policies

Asymmetric encryption, also known as public-key cryptography, is a type of encryption that uses a pair of keys to encrypt and decrypt data. The pair of keys includes a public key, which can be shared with anyone, and a private key, which is kept secret by the owner. In asymmetric encryption, the sender uses the recipient’s public key to encrypt the data. The recipient then uses their private key to decrypt the data. This approach allows for secure communication between two parties without the need for both parties to have the same secret key. RSA is one of the most commonly used asymmetric encryption algorithms. It is based on the mathematical problem of factoring large numbers, which is believed to be hard to solve. RSA stands for Rivest-Shamir-Adleman, the names of the three inventors of the algorithm. RSA can be used for both encryption and digital signatures. To generate an RSA key pair, the following steps are performed:

• Choose two large prime numbers, p and q, and compute their product, n = pq. This is called the modulus.
• Choose a small number, e, that is relatively prime to (p-1)(q-1). This is called the public exponent.
• Compute a number, d, that satisfies the equation ed ≡ 1 (mod (p-1)(q-1)). This is called the private exponent.
• The public key is (n, e) and the private key is (n, d).

To encrypt a message, m, with the public key (n, e), the following formula is used:

• c = m^e mod n

To decrypt a ciphertext, c, with the private key (n, d), the following formula is used:

• m = c^d mod n

References :=

• [Implementing and Operating Cisco Security Core Technologies (SCOR) v1.0], Module 3: VPN Technologies, Lesson 3.1: Site-to-Site VPNs, Topic 3.1.2: IPsec VPNs
• What is Asymmetric Encryption? - GeeksforGeeks
• What is asymmetric encryption? | Asymmetric vs. symmetric … - Cloudflare