Introduction to Information Security

Understanding key terminologies in computer security and learning cryptographic techniques for authentication.

It marked the beginning of computer networking, paving the way for the internet.

Privacy is individual-centric, governing personal information release, while security is system-centric, aiming to protect user data.

<p>Unauthorized information release, unauthorized modification, and unauthorized denial of use (DoS).</p> Signup and view all the answers

<p>The negative goal focuses on preventing all violations, while the positive goal aims to ensure practical, reliable safeguards.</p> Signup and view all the answers

<p>Saltzer's insights address foundational issues in information security that remain relevant today.</p> Signup and view all the answers

<p>An unprotected system has no meaningful protection mechanisms in place.</p> Signup and view all the answers

<p>The first email was intended as a useful communication tool.</p> Signup and view all the answers

<p>It provides a binary choice of complete access or no access at all.</p> Signup and view all the answers

<p>Level 2 enables selective sharing based on access lists, allowing for controlled interactions.</p> Signup and view all the answers

<p>It allows users to assign different access rights to files based on ownership and groups.</p> Signup and view all the answers

<p>It uses user-defined strings or tags to restrict access based on security classifications.</p> Signup and view all the answers

<p>It emphasizes that security mechanisms should be simple and minimal.</p> Signup and view all the answers

<p>To ensure that access is denied by default, requiring explicit permissions for access.</p> Signup and view all the answers

<p>It requires that every access to a resource be checked for authorization without exception.</p> Signup and view all the answers

<p>It ensures security does not depend on secrecy of the design, allowing for public scrutiny.</p> Signup and view all the answers

<p>It aims to reduce the risk by requiring multiple conditions for access.</p> Signup and view all the answers

<p>It ensures users and programs operate with the minimum privileges required.</p> Signup and view all the answers

<p>It minimizes shared mechanisms to reduce risks if one mechanism has a flaw.</p> Signup and view all the answers

<p>It ensures that security measures are easy to understand and use for users.</p> Signup and view all the answers

<p>They focus on positive security goals and are still relevant to modern systems.</p> Signup and view all the answers

<p>Design systems to make breaking security protections computationally infeasible.</p> Signup and view all the answers

<p>Detection is emphasized as a more practical approach than attempting to prevent every possible attack.</p> Signup and view all the answers

<p>To enable students to securely access their personal files from any workstation on the campus.</p> Signup and view all the answers

<p>'Virtue' refers to the client workstations, while 'vice' refers to the centralized server environment where user files are stored.</p> Signup and view all the answers

<p>Encryption was necessary to secure data transmission and prevent eavesdropping over the insecure local area network.</p> Signup and view all the answers

<p>The Venus process authenticates users and manages local file caching on client workstations.</p> Signup and view all the answers

<p>AFS allowed for seamless access to personal content across different devices, similar to how cloud services function today.</p> Signup and view all the answers

<p>Assuming that LANs were untrusted led to the implementation of robust security measures to protect user data.</p> Signup and view all the answers

<p>RPC allows the Venus process to request files from vice servers, enabling efficient communication within the system.</p> Signup and view all the answers

<p>The client workstations ran a variant of the Unix operating system.</p> Signup and view all the answers

<p>It securely authenticates users and encrypts data transmitted between clients and servers.</p> Signup and view all the answers

<p>Private key cryptosystems use symmetric keys while public key cryptosystems use asymmetric keys.</p> Signup and view all the answers

<p>It stores frequently accessed files on local disks, reducing network load and improving access speed.</p> Signup and view all the answers

<p>It allows users to access their files from any location without needing manual file transfers.</p> Signup and view all the answers

<p>Private key systems require complex secure key distribution, whereas public key systems allow for simplified distribution as the public key is openly shared.</p> Signup and view all the answers

<p>AFS demonstrated secure authentication and the feasibility of distributed file systems over insecure networks.</p> Signup and view all the answers

<p>Private key systems face scalability issues due to the challenges of distributing a unique key to multiple participants.</p> Signup and view all the answers

<p>The sender's identity is sent in cleartext to allow the recipient to determine which key to use for decryption.</p> Signup and view all the answers

<p>The key distribution problem makes it difficult to securely share private keys among many users.</p> Signup and view all the answers

<p>It allows anyone to encrypt messages using the receiver's public key without needing to share private keys.</p> Signup and view all the answers

<p>A major challenge is the secure exchange and management of private keys between communicating parties.</p> Signup and view all the answers

<p>Public key systems address the key distribution problem by separating encryption and decryption keys, enabling secure communication without prior key exchanges.</p> Signup and view all the answers

<p>A mathematical function that is easy to compute in one direction but hard to reverse without the private key.</p> Signup and view all the answers

<p>In private key systems, both parties use the same key; in public key systems, the sender uses the receiver's public key for encryption.</p> Signup and view all the answers

<p>Replay attacks involve capturing and resending packets, tricking the sender or receiver if the system fails to detect such actions.</p> Signup and view all the answers

<p>It emphasizes that while the encryption algorithm may be public knowledge, the security relies on keeping the key confidential.</p> Signup and view all the answers

<p>Secure RPC allows for encrypted communication, ensuring confidentiality and integrity while manageable key distribution is possible.</p> Signup and view all the answers

<p>The mathematical relationships between the keys are designed to make reversing the process without the private key extremely difficult.</p> Signup and view all the answers

<p>Overuse increases the likelihood of key exposure and vulnerability to attacks, leading to potential security breaches.</p> Signup and view all the answers

<p>It allows users to immediately access their personal files on any workstation without delays.</p> Signup and view all the answers

<p>It suggests that encryption algorithms can be openly published and scrutinized, reinforcing that security relies on protecting keys, not the algorithms.</p> Signup and view all the answers

<p>The early adoption of private key cryptography significantly improved security.</p> Signup and view all the answers

<p>It refers to the design of encryption methods that make it impractical to break the encryption without the appropriate key.</p> Signup and view all the answers

<p>Private key cryptosystems (symmetric) and public key cryptosystems (asymmetric).</p> Signup and view all the answers

<p>User isolation ensures that each user's data and actions remain protected from unintended or malicious interference by others.</p> Signup and view all the answers

<p>Scalability is impacted by the difficulty of securely distributing unique keys to each participant as user numbers increase.</p> Signup and view all the answers

<p>Processes like Venus verify user identities, ensuring secure communication with servers.</p> Signup and view all the answers

<p>Public key systems are favored because they simplify secure key sharing, making secure communication feasible in open networks.</p> Signup and view all the answers

<p>Its architecture and principles have greatly influenced the design of current cloud computing infrastructures.</p> Signup and view all the answers

<p>Mutual authentication ensures that both the client and server verify each other's identities, establishing trust before any communication occurs.</p> Signup and view all the answers

<p>Fresh random numbers and their increments ensure that old messages cannot be reused by attackers, as each message is unique due to this variation.</p> Signup and view all the answers

<p>The HKC is used solely for the initial authentication and establishing secure RPC sessions, limiting its exposure in ongoing operations.</p> Signup and view all the answers

<p>Generating a unique SK for each session enhances security by ensuring that the compromise of one session key does not affect others.</p> Signup and view all the answers

<p>Sequence numbers ensure that messages are processed in a defined order and are unique, which protects against replay attacks.</p> Signup and view all the answers

<p>Minimizing credential exposure is crucial to reduce the risk of interception and misuse by attackers.</p> Signup and view all the answers

<p>Transitioning to SK for file system operations reduces the frequency and exposure of HKC during communications, limiting potential vulnerabilities.</p> Signup and view all the answers

<p>Secure session establishment ensures that all interactions between the client and server are authenticated and encrypted, fostering a trustworthy environment.</p> Signup and view all the answers

<p>Each RPC session requires a new SK, generated and encrypted with HKC, ensuring that each session is authenticated independently.</p> Signup and view all the answers

<p>The client sends its ID and an encrypted message, which the server decrypts to retrieve the handshake key and other parameters before responding with its own encrypted message.</p> Signup and view all the answers

<p>Limiting their use reduces the risk of long-term exposure and potential compromise.</p> Signup and view all the answers

<p>Ephemeral IDs and keys are temporary credentials that secure communication during RPC sessions.</p> Signup and view all the answers

<p>The user provides their username and password, which is securely sent to the login server for authentication.</p> Signup and view all the answers

<p>The clear token contains the Handshake Key for communication, while the secret token serves as an ephemeral client ID.</p> Signup and view all the answers

<p>Secure RPC ensures encrypted communication and protects data integrity over insecure networks.</p> Signup and view all the answers

<p>Regularly managing keys mitigates risks associated with potential cracking and unauthorized access.</p> Signup and view all the answers

<p>The classes are login (initial authentication), RPC session establishment, and file system access during an RPC session.</p> Signup and view all the answers

<p>Usability is enhanced by limiting credential exposure, while security is maintained through ephemeral credentials.</p> Signup and view all the answers

<p>Venus acts as a surrogate for the user, handling file operations like fetching, caching, and committing changes.</p> Signup and view all the answers

<p>Encryption protects sensitive information like usernames and passwords during transmission over insecure links.</p> Signup and view all the answers

<p>Ephemeral credentials limit the potential for long-term credential compromise and enhance session security.</p> Signup and view all the answers

<p>It securely establishes the user's identity and initial connection to the server for further interactions.</p> Signup and view all the answers

<p>It allows transactions to be securely managed with ephemeral credentials, ensuring data integrity and confidentiality.</p> Signup and view all the answers

<p>HKC is used to establish secure channels for RPC sessions, facilitating data transmission between Venus and Vice.</p> Signup and view all the answers

<p>HKC acts as a private key for secure communication, allowing Venus to establish secure RPC sessions with Vice.</p> Signup and view all the answers

<p>The Secret Token serves as a unique client ID for the session, preventing exposure of sensitive credentials like the username and password.</p> Signup and view all the answers

<p>Venus discards both the secret and clear tokens to prevent unauthorized reuse or compromise.</p> Signup and view all the answers

<p>Venus sends its Secret Token in clear text and encrypts a random number Xᵣ using the HKC to initialize the RPC session.</p> Signup and view all the answers

<p>Vice decrypts the Secret Token to retrieve the Clear Token and extracts the HKC for further communication.</p> Signup and view all the answers

<p>Random numbers ensure freshness in each session and help prevent replay attacks by verifying expected increments.</p> Signup and view all the answers

<p>Vice authenticates Venus by expecting Xᵣ + 1, while Venus authenticates Vice by expecting Yᵣ + 1 in their respective responses.</p> Signup and view all the answers

<p>Ephemeral credentials reduce the risk of credential exposure and enhance security over insecure networks.</p> Signup and view all the answers

<p>The Bind Mechanism ensures secure client-server connections by using tokens and HKC to authenticate and encrypt messages.</p> Signup and view all the answers

<p>The Secret Token is transmitted securely over insecure links, being encrypted to prevent unauthorized access during transit.</p> Signup and view all the answers

<p>The established communication is authenticated and encrypted, ensuring secure interaction between Venus and Vice.</p> Signup and view all the answers

<p>The Clear Token contains the HKC and serves as a data structure known to the login process for secure communication.</p> Signup and view all the answers

<p>Using them only once minimizes the long-term risk of credential exposure and protects users' sensitive information.</p> Signup and view all the answers

<p>The tokens enable secure RPC sessions, allowing Venus to securely communicate with Vice while ensuring user authentication.</p> Signup and view all the answers

<p>Messages are encrypted using the Handshake Key for Client (HKC), ensuring confidentiality during exchange.</p> Signup and view all the answers

Critical in today's connected world, requiring dedicated courses and degrees.

Essential concepts in computer security, understanding key terms.

Preventing information leaks without owner consent.

Ensuring data integrity, preventing unauthorized changes.

Unauthorized denial of use, preventing authorized user access.

Privacy is individual-centric, security is system-centric.

Ensuring users are who they claim to be.

Fundamental issues in information security, remain relevant.

Preventing mistakes does not automatically create a secure system.

All-or-nothing access; either full access or no access.

Controlled sharing based on access lists.

Users define sharing controls/permissions

Access based on data labels/security levels

Security needs to adapt and change over time.

Security mechanisms should be simple and minimal.

Deny access by default; explicit permission needed

Every access must be checked for authorization.

Security doesn't depend on secrecy.

Multiple conditions/credentials needed for access

Users/programs use only necessary privileges

Minimize shared security mechanisms.

Security should be easy for users.

Make breaking security computationally hard.

Focus on detecting breaches, not preventing all attacks.

AFS aimed to secure user files from unauthorized access even when transmitted over an insecure local area network (LAN).

AFS assumed that the LAN, connecting workstations and servers, was untrusted, meaning data could be intercepted.

Venus is a process running on each client workstation (virtue) responsible for user authentication, local file caching, and communication with servers.

AFS encrypts data transmitted over the insecure LAN to prevent eavesdropping. Inside the servers (vice), communication is secure without encryption.

Vice is the server environment where user files are stored centrally. Communication within Vice is secure and does not require encryption.

Remote Procedure Calls (RPCs) are used by Venus to request files from Vice servers. Venus essentially acts as a user's representative.

AFS was an early example of a distributed file system with strong security, influencing modern cloud computing and file synchronization.

AFS allows users to access their personal files from any workstation on campus, making files seem locally stored upon login.

Remote Procedure Call (RPC) communication that is protected by encryption, ensuring confidentiality of data sent and received between clients and servers.

Encryption method where both sender and receiver use the same secret key for both encryption and decryption, requiring a shared secret for communication.

Encryption method using a pair of linked keys: a public key for encryption and a private key for decryption. The public key is widely shared, while the private key remains secret.

A mathematical operation that is easy to perform in one direction (encryption) but extremely difficult to reverse without the private key (decryption).

The challenge of securely sharing and managing private keys in private key cryptography, especially when dealing with many users or devices.

The encrypted version of data, appearing as random or meaningless information to unauthorized parties.

Security principle that states that the design of a system should be openly published, but the key used for encryption should be kept secret.

A pioneering distributed file system developed at Carnegie Mellon University, emphasizing secure access to files over potentially insecure networks.

Storing frequently accessed files locally on a device to reduce network traffic and improve performance.

File systems designed to store and manage data across multiple connected computers, allowing users to access files remotely.

A critical component of the AFS system that verifies user identities and manages secure interactions with servers.

Modern services based on the principles of distributed files systems, allowing users to store and access files from multiple devices and keep them synchronized across different locations.

The lasting impact of AFS on the design and development of modern distributed systems, including concepts like secure authentication, file caching, and distributed file storage.

The process of converting data into ciphertext using an encryption algorithm and a key, and then converting the ciphertext back into the original data using decryption.

The public and private keys in public key cryptography, related mathematically but not derivable from each other.

A system where the same key is used for both encryption and decryption, requiring secure key exchange between parties.

A system using separate keys for encryption (public) and decryption (private), allowing secure communication without prior key exchange.

The process of safely sharing secret keys between parties in a private key system.

The process of generating, storing, distributing, and revoking keys in any cryptosystem.

Encryption method using the same key for both encryption and decryption.

Encryption method using a pair of keys, one for encryption and the other for decryption.

Sending the identity of the sender in unencrypted form so the receiver can identify the correct key for decryption.

An attacker intercepts a message and replays it later to deceive the recipient.

Verifying that the server communicating with a user is legitimate, preventing imposter impersonation.

Confirming that the user logging into the system is who they claim to be.

Using the same key repeatedly, increasing the risk of it being compromised by attackers.

Repetitive use of the same username/password combination, potentially weakening security.

The controlled management of user identities and access permissions, preventing sensitive information exposure.

Both client and server prove their identities to each other during a secure connection. This ensures that neither party is an imposter.

Using unique, changing values to prevent attackers from reusing old messages to gain access.

Setting up a protected connection between client and server, guaranteeing secure and authenticated communication.

A shared secret key used only during the initial connection setup to prove identities and establish a secure session.

A unique, temporary key created for each secure communication session, acting as the handshake key for the entire communication.

Using SK for communication within the session protects the HKC, which is only used briefly, minimizing its risk of compromise.

Sequence numbers ensure that messages are processed in their correct order and prevent replay attacks.

AFS encrypts data transmitted over the insecure network to protect it from eavesdropping, ensuring the confidentiality of user files.

Venus is the client software that makes requests to the server (Vice) on behalf of the user, handling communication and file access.

By using encryption for communication, AFS safeguards user files from unauthorized access even when transmitted over an insecure network.

The Handshake Key for Client (HKC) acts as a private key enabling secure communication between Venus and Vice.

HKC is extracted from the clear token received by Venus during the initial login and used to establish secure RPC sessions for future interactions.

The secret token acts as a unique client ID that represents the user during the login session.

Venus uses the secret token as the client ID and the HKC for encryption and decryption in all subsequent communication with Vice.

Both the secret token and the clear token are discarded by Venus to ensure security and prevent credential reuse.

Ephemeral credentials, like the secret token and HKC, are temporary and used only for a specific session, reducing the risk of credential exposure over time.

Using ephemeral credentials enhances security by minimizing the risk of credential compromise over time.

The bind mechanism uses the secret token and HKC to establish secure RPC sessions, ensuring trusted communication between Venus and Vice.

Venus initiates the bind process by sending the secret token and an encrypted message to Vice. Vice decrypts, validates, and responds with encrypted confirmations, ultimately establishing a secure connection.

Using random numbers (Xᵣ and Yᵣ) ensures the freshness of each session, preventing attackers from replaying old messages to gain access.

The HKC, along with the secret token, enables secure and encrypted communication between Venus and Vice over potentially insecure network links.

The bind operation incorporates mutual authentication by exchanging encrypted messages with expected values (Xᵣ + 1 and Yᵣ + 1) to confirm the identity of both parties.

Ephemeral credentials like the secret token and HKC reduce the risk of credential exposure, enhancing security over insecure network connections.

The process aims to securely establish an RPC session between Venus and Vice, authenticating both client and server, and mitigating replay attacks to ensure secure communication.

A distributed file system designed for secure file sharing across a campus network, protecting user files from unauthorized access.

A client process that runs on each workstation, handling user authentication, local file caching, and secure communication with the server.

The server environment where files are stored centrally. Communication within Vice is secure.

Utilizing encryption to protect data transmitted over potentially insecure networks.

Short-lived, temporary credentials used for one session, reducing the risk of exposure.

The initial authentication method where users provide their username and password to access the system.

An encrypted bit string used as an ephemeral client ID for the session, generated during login.

A data packet containing the Handshake Key (HKC) used for secure communication, encrypted with a key known only to the server.

The process of establishing a secure communication channel (RPC session) between Venus and Vice for file operations.

The process of interacting with files during an RPC session, fetching, caching, modifying, and committing changes securely.

The process of using the secret token and HKC to establish a secure RPC session between the client (Venus) and server (Vice).