In designing Private Mirror and other Private Sky components, our goal is to ensure that messages are never available in the clear even after “First Unlock” on an IOS device, we have been using AI tools including ChatGPT to speed up the development of a protocol and App suite we think will be critically needed in 2025.
We’d like to share some of that analysis.
1 Not all AES flavors are the same
AES has three standard key sizes:
AES-128: 128-bit key
AES-192: 192-bit key
AES-256: 256-bit key
These are the only key sizes supported by AES as defined by the National Institute of Standards and Technology (NIST).
2. There is no legit version of AES with a key size greater than 256
These terms are likely misunderstandings or mislabeling:
There is no official AES standard for keys larger than 256 bits.
The numbers (e.g., 1024, 2048) might come from confusion with RSA encryption, which uses much larger key sizes because it relies on a different mathematical basis (asymmetric encryption and prime factorization).
3. Why Larger AES Keys Aren't Necessary
AES-256 is considered secure enough for all practical purposes:
It offers exponential growth in security compared to AES-128 or AES-192. For example, breaking AES-256 by brute force would require 22562256 operations, which is computationally infeasible with current and foreseeable technology.
Doubling or tripling the key size does not offer meaningful additional protection. Larger key sizes in symmetric encryption can sometimes reduce performance without improving security proportionally.
4. Should You Use AES-256 Over AES-128?
The choice depends on your needs:
AES-128: Faster and still highly secure for most applications.
AES-256: Offers higher security for scenarios where resistance to future threats (like quantum computing) or extreme attack vectors is a concern.
5. Quantum Threats
Quantum computing could theoretically impact AES's security:
Grover's algorithm could reduce the effective key size by half (e.g., AES-256 could be reduced to 128-bit security).
Using AES-256 ensures more resilience to potential quantum attacks than AES-128.
Conclusion
AES-256 is the largest official key size and provides robust security. Terms like "AES-1024" or "AES-2048" are likely either mislabeling or confusion with RSA or other encryption systems. Stick to official AES key sizes (128, 192, 256), with AES-256 being the strongest option.
4o
You said:
Thanks and how long would it take a 2000 qubit quantum computer to crack or a quantum annesling d-wave 4000
AES 256 Vulnerabilities
The time it would take for a quantum computer or an annealing system like D-Wave to crack AES encryption depends on the computational model, type of attack, and assumptions about future quantum computing capabilities. Here's a breakdown of the relevant considerations:
1. Quantum Computers and AES
Quantum computers, such as a 2000-qubit quantum computer, are often evaluated for their ability to use Grover's algorithm to attack symmetric encryption like AES.
Grover's Algorithm
Grover's algorithm provides a quadratic speedup for brute-force search:
Instead of 2n2n operations to test all keys for an nn-bit key, it would require roughly 2n/22n/2 operations.
For AES-128: Effective strength is reduced to 264264 operations.
For AES-256: Effective strength is reduced to 21282128 operations.
Time to Crack AES with a 2000-Qubit Quantum Computer
The actual time depends on several factors:
Gate Quality and Clock Speed: Current gate speeds are slow compared to classical processors.
Error Rates: High error rates in modern quantum computers reduce effective computational power.
Number of Logical Qubits: A 2000-qubit machine doesn't imply 2000 logical qubits—many are required for error correction.
Parallelization: Grover's algorithm is not trivially parallelizable.
Even a perfect 2000-qubit quantum computer would take millions of years to break AES-256 due to the effective 21282128 operations required. For AES-128, with 264264 operations, it might theoretically crack it in days to months(with idealized qubits and speeds).
2. Quantum Annealers (e.g., D-Wave 4000)
Quantum annealers like D-Wave are not general-purpose quantum computers and cannot run Grover's algorithm. They are designed for solving optimization problems, not for tasks like brute-forcing AES keys.
Limitations of Quantum Annealers:
They are not capable of running Shor’s or Grover’s algorithms.
They perform well on specific optimization problems but lack the universal capability of gate-based quantum computers.
Conclusion: A D-Wave 4000 or similar annealer cannot be used to attack AES encryption directly.
3. Practical Quantum Threat Timeline
Current Status: No existing quantum computer can break AES-128 or AES-256 in any feasible timeframe.
Future Projections:
Experts estimate that a large-scale, fault-tolerant quantum computer capable of breaking AES-256 might not emerge for decades (beyond 2040).
For Grover's algorithm, breaking AES-256 would require a machine with millions of high-quality logical qubits and extremely fast clock speeds.
Conclusion
A 2000-qubit quantum computer: Far from capable of breaking AES-256; likely infeasible even for AES-128.
D-Wave 4000 quantum annealer: Not designed for this task and cannot attack AES.
AES-256 remains secure against current and near-term quantum threats. Future-proofing for quantum attacks may require transitioning to post-quantum cryptographic algorithms, but this is not an immediate concern for AES.
4o
You said:
I read that shor algo has been run on d-wave
ChatGPT said:
ChatGPT
Shor's algorithm, a quantum algorithm designed for integer factorization, is typically implemented on gate-based quantum computers. D-Wave systems, however, utilize quantum annealing—a different computational model optimized for solving optimization problems rather than executing gate-based algorithms like Shor's.
While D-Wave's architecture isn't suited for directly running Shor's algorithm, researchers have explored alternative methods to factor integers using quantum annealing. For instance, a study demonstrated the factorization of the number 291,311 using a D-Wave 2X quantum processor by formulating the problem into a form suitable for quantum annealing
. Another research effort factored the number 1,005,973 using a D-Wave system, highlighting the potential of quantum annealers in integer factorization tasks
.
These approaches differ from Shor's algorithm and are tailored to leverage the strengths of quantum annealing. Therefore, while D-Wave systems have been used for integer factorization, they do not execute Shor's algorithm in the traditional sense.
Sources
4o
You said:
Recent research proves that under certain conditions, quantum annealing computers can run algorithms — including the well-known Shor’s algorithm — more quickly than classical computers. In most cases, however, quantum annealing does not provide a speedup compared to classical computing when time is limited, according to a study in Nature Communications.
ChatGPT said:
ChatGPT
Recent research indicates that quantum annealing computers can outperform classical computers in specific scenarios, including executing algorithms like Shor's algorithm. However, this advantage is limited to particular conditions; generally, quantum annealing does not offer a speedup over classical computing when time constraints are present.
Quantum annealing is a quantum computing method primarily designed to solve optimization problems by finding the global minimum of a function. While it has shown promise in certain applications, its effectiveness compared to classical algorithms varies depending on the problem and the computational resources available.
In the context of Shor's algorithm, which is used for integer factorization, traditional implementations are tailored for gate-based quantum computers rather than quantum annealers. Nonetheless, researchers have explored alternative methods to adapt factorization problems for quantum annealing systems. For example, a study demonstrated the factorization of the number 291,311 using a D-Wave 2X quantum processor by formulating the problem into a form suitable for quantum annealing.
These findings suggest that while quantum annealing can offer advantages in specific cases, its general applicability and speedup over classical computing are limited and highly dependent on the nature of the problem and the computational context.
Sources
4o
You said:
I see what level of advancement would be required to break aes 256 in quebits
ChatGPT said:
ChatGPT
Breaking AES-256 using a quantum computer primarily involves using Grover's algorithm, which provides a quadratic speedup for brute-force key search. Here's what would be required:
1. Theoretical Requirements to Break AES-256
AES-256 Key Space: 22562256
Grover’s Algorithm: Reduces the effective key space to 21282128, requiring approximately 21282128 operations to find the key.
Qubits Required:
Logical Qubits: Implementing Grover's algorithm for AES-256 requires around 256 logical qubits to represent the key, plus additional qubits for control, storage, and error correction. The exact number depends on the implementation but could range between 500 and 1000 logical qubits.
Physical Qubits: Due to error correction requirements, the ratio of physical to logical qubits is very high. Estimates suggest:
For state-of-the-art error correction: 1 logical qubit ≈ 1000 physical qubits.
Total required physical qubits: 500,000 to 1,000,000 physical qubits.
Gate Depth and Runtime:
Grover’s algorithm for AES-256 involves 21282128 iterations of quantum gates.
Each iteration involves a quantum circuit for evaluating the AES function, which would require a gate depth in the trillions.
With current quantum gate speeds, running 21282128 iterations could take an infeasible amount of time (millions of years).
2. Practical Advancements Needed
To break AES-256, the following advancements in quantum computing are necessary:
Fault-Tolerant Quantum Computing:
Modern quantum computers are noisy and prone to errors. Breaking AES-256 would require robust error correction to maintain coherence across trillions of operations.
High-Quality Logical Qubits:
At least 500–1000 logical qubits with extremely low error rates.
Improved Physical Qubit Scaling:
Current quantum computers have a few thousand physical qubits. Scaling to millions of physical qubitswould require significant breakthroughs in quantum hardware and materials science.
Faster Gate Speeds:
Quantum gates must execute operations much faster than current speeds to handle 21282128 iterations in a reasonable time.
3. Current State and Timeline
The most advanced gate-based quantum computers today (e.g., IBM, Google) have fewer than 200 high-quality physical qubits.
Researchers estimate that a large-scale, fault-tolerant quantum computer capable of breaking AES-256 is likely 20–30 years away (if achievable at all).
Current quantum computers are far from the level needed to threaten AES-256.
Conclusion
To break AES-256, you would need:
500,000–1,000,000 physical qubits for fault-tolerant operations.
Significantly faster gate speeds and more efficient error correction.
Quantum computers capable of performing 21282128 operations in a feasible timeframe.
At present, AES-256 remains quantum-resistant, and developing quantum-proof encryption schemes (like post-quantum cryptography) is more of a proactive measure than an immediate necessity.
4o
You said:
Thanks
ChatGPT said:
ChatGPT
You're welcome! If you have any more questions about encryption, quantum computing, or anything else, feel free to ask. Happy learning!
4o
You said:
which is more secure Signal protocol or AES 256
ChatGPT said:
ChatGPT
The Signal protocol and AES-256 are both cryptographic components, but they serve different purposes and cannot be directly compared as one being "more secure" than the other. Here's how they differ and complement each other:
1. What Is AES-256?
Type: Symmetric Encryption Algorithm
Purpose: Encrypts and decrypts data using the same key.
Strength:
Extremely secure when implemented correctly.
Provides confidentiality, but does not inherently handle authentication or key exchange.
Limitations: Requires secure key management and does not provide end-to-end encryption by itself.
2. What Is the Signal Protocol?
Type: Secure Communication Protocol
Purpose: A cryptographic framework for secure messaging, providing end-to-end encryption for real-time communication.
Key Features:
Combines multiple cryptographic algorithms, including AES-256, for different purposes.
Uses a combination of Double Ratchet Algorithm, X3DH key agreement protocol, and prekeys for forward secrecy and post-compromise security.
Encrypts messages, handles key exchanges, and ensures integrity.
Strength:
Highly secure for real-time messaging.
Designed to mitigate threats like key compromise with features like forward and backward secrecy.
Limitations: Specifically designed for messaging and communication, not general-purpose encryption.
Key Comparisons
FeatureAES-256Signal ProtocolPurposeSymmetric encryption for data security.End-to-end encryption for communication.Encryption TypeSymmetric (one key for encryption and decryption).Combines symmetric and asymmetric methods.Key ManagementExternal system required for key exchange.Built-in secure key exchange mechanism.Forward SecrecyNo. If the key is compromised, all data is exposed.Yes. Past communications remain secure.Post-Compromise SecurityNo. Key compromise affects future data.Yes. Key rotation ensures future data security.Use CasesGeneral-purpose encryption (e.g., file storage).Real-time messaging and communication.
Which Is More Secure?
For General Data Security: AES-256 is robust for encrypting data like files, databases, or storage. Its security is tied to key management and implementation quality.
For Messaging and Communication: The Signal Protocol is superior because it provides:
Forward and backward secrecy.
Built-in mechanisms for secure key exchanges.
Resistance to real-time attacks (e.g., man-in-the-middle).
When Do They Work Together?
In practice, protocols like the Signal Protocol use AES-256 as part of their cryptographic toolkit. For example:
AES-256 is used for encrypting message contents.
Signal adds layers like asymmetric cryptography (e.g., ECDH key exchange) to provide features like key agreement and perfect forward secrecy.
Conclusion
Signal Protocol is more secure for communication because it offers features beyond what AES-256 alone can provide.
AES-256 remains unmatched for general-purpose encryption tasks requiring high security.
If you're choosing a secure messaging system, Signal Protocol (as implemented in apps like Signal or WhatsApp) is the way to go. For data-at-rest, AES-256 is the gold standard.
4o
You said:
As of today Signal protocol has been cracked is that a threat to AES 256
ChatGPT said:
ChatGPT
As of November 21, 2024, there is no credible evidence to suggest that the Signal Protocol has been compromised. The Signal Protocol, which underpins the Signal messaging app and other platforms, employs a combination of cryptographic algorithms, including AES-256, to ensure secure communication.
Understanding the Signal Protocol and AES-256:
Signal Protocol: This is an end-to-end encryption protocol designed to provide secure messaging. It combines several cryptographic techniques, including the Double Ratchet Algorithm, prekeys, and the Extended Triple Diffie–Hellman (X3DH) handshake, utilizing primitives like Curve25519, AES-256, and HMAC-SHA256. The protocol ensures confidentiality, integrity, authentication, and forward secrecy in communications.
AES-256: The Advanced Encryption Standard (AES) with a 256-bit key length is a symmetric encryption algorithm widely recognized for its robustness and security. It is used globally to secure sensitive data across various applications.
Relationship Between Signal Protocol and AES-256:
The Signal Protocol incorporates AES-256 as one of its cryptographic primitives. Specifically, AES-256 is used for encrypting message contents within the protocol. Therefore, the security of the Signal Protocol is partly dependent on the strength of AES-256.
Implications of a Hypothetical Compromise:
If the Signal Protocol Were Compromised: A breach in the Signal Protocol would indicate vulnerabilities in its overall design or implementation. However, this does not necessarily imply a weakness in AES-256 itself. The compromise could stem from other components or the integration of various cryptographic elements within the protocol.
If AES-256 Were Compromised: Since AES-256 is a fundamental part of the Signal Protocol, any vulnerability in AES-256 would directly impact the security of the Signal Protocol and any other systems relying on AES-256 for encryption.
Current Status:
As of the latest available information, both the Signal Protocol and AES-256 remain secure and are widely trusted in the cryptographic community. No credible reports or research have indicated that either has been compromised.
Conclusion:
The security of the Signal Protocol and AES-256 are interrelated but distinct. A compromise in the Signal Protocol does not inherently mean that AES-256 is compromised, and vice versa. Both continue to be considered secure as of the current date.
Sources
4o
You said:
an israeli firm has claimed to be able to crack it, now is AES 256 also in danger
ChatGPT said:
ChatGPT
Recent claims by Israeli firm Cellebrite suggest they can access data from the Signal app on unlocked devices in their possession. It's important to clarify that this does not indicate a compromise of the Signal Protocol's end-to-end encryption or the underlying AES-256 encryption algorithm.
Understanding the Claims:
Cellebrite's Capability: Cellebrite's tools are designed to extract data from devices that are unlocked and physically accessible. Their claim pertains to accessing data stored on such devices, not intercepting or decrypting encrypted communications in transit.
Signal's Encryption: The Signal Protocol employs AES-256 as part of its encryption suite to secure messages during transmission. This end-to-end encryption ensures that only the communicating parties can read the messages. Cellebrite's method does not break this encryption; instead, it accesses data on the device when it is unlocked and in their possession.
Implications for AES-256:
AES-256 Security: AES-256 remains a robust and widely trusted encryption standard. The ability to extract data from an unlocked device does not equate to breaking the AES-256 encryption itself. There is no evidence to suggest that AES-256 has been compromised.
Conclusion:
The claims by Cellebrite do not indicate a vulnerability in the Signal Protocol's end-to-end encryption or the AES-256 algorithm. These tools require physical access to an unlocked device and do not compromise the security of encrypted communications. AES-256 continues to be considered secure for protecting sensitive information.
Sources
4o
You said:
so if the messages were still encrypted on an unlocked device they would not be able to access it
ChatGPT said:
ChatGPT
Correct! If the messages on the unlocked device were still encrypted and the decryption keys were not accessible, even a sophisticated tool like Cellebrite would not be able to read them.
How This Works
Encrypted Data: If the Signal app (or any other app) stores messages in an encrypted format on the device, accessing the raw data wouldn't provide readable information without the decryption key.
Decryption Keys: For end-to-end encrypted apps like Signal, the keys used to decrypt messages are typically:
Ephemeral (only in memory during active use of the app).
Not stored persistently in an accessible form.
What Happens with an Unlocked Device?
Unlocked Device Access: If the device is unlocked, Cellebrite (or similar tools) can:
Access the app's decrypted data if the app is open and actively being used.
Potentially access temporary files or caches where decrypted messages are stored.
Encrypted Data: If messages are still encrypted, or the keys are unavailable (e.g., stored securely or wiped after use), the data would remain unreadable.
Signal's Security Practices
On-Device Encryption: Signal encrypts its message database using the device's hardware security module (e.g., Secure Enclave on iPhones or Trusted Execution Environment on Android).
Key Protection:
Keys for decrypting the message database are tied to the device's security features (e.g., biometric authentication or device PIN).
Without the correct authentication, even an unlocked device might not expose these keys.
Conclusion
If Signal's messages are still encrypted on the unlocked device, and the decryption keys are not accessible, Cellebrite or similar tools cannot access the content. This highlights the importance of robust encryption practices and secure key storage for protecting sensitive data, even in cases where physical access to a device is gained.
4o
You said:
so signal on an apple mobile device relies on first boot
ChatGPT said:
ChatGPT
Yes, Signal (and many other secure apps) on Apple devices rely heavily on the First Boot Security Model and the hardware-based encryption mechanisms provided by the iPhone. Here's a breakdown of how this works:
1. First Boot Security on iOS
The first boot refers to the state of the device after a full shutdown, where the device has not been unlocked since it was powered on.
Encryption on First Boot:
On iOS, the entire file system is encrypted with a key that is derived from the user's passcode and a hardware key stored in the Secure Enclave.
Until the user unlocks the device for the first time (by entering their passcode), the decryption key is unavailable, and sensitive data (like app databases, including Signal messages) remains inaccessible.
Signal's Message Storage:
Signal encrypts its message database on the device using AES-256 encryption, with keys protected by iOS's Data Protection API.
Before the first unlock, even if someone physically accesses the device, Signal's database remains securely encrypted and unreadable.
2. After First Unlock
Once the user unlocks the device:
The decryption keys are loaded into memory, enabling apps to access protected data.
Some keys remain accessible for background operations until the device is locked again, depending on the Data Protection Class assigned to each file.
Signal's Approach:
Signal ensures that its message database is tied to the Complete Protection class, meaning it is inaccessible when the device is locked.
3. Implications for Cellebrite or Similar Tools
Before First Unlock:
If Cellebrite gains physical access to a device but it hasn't been unlocked since power-on, they cannot access Signal's database or any other protected data.
This is because the hardware encryption key required for decryption isn't available until the user enters their passcode.
After First Unlock:
If the device is unlocked or has been unlocked since power-on, tools like Cellebrite may attempt to extract decrypted data if it's temporarily accessible in memory or cached.
Signal mitigates this risk by encrypting its database and tying access to the device's secure environment, reducing the likelihood of exposure even on an unlocked device.
4. Best Practices for Signal Users
To maximize security:
Restart the Device Regularly:
Restarting your iPhone ensures that the device returns to the "first boot" state, where all sensitive data is inaccessible until the user enters the passcode.
Use a Strong Passcode:
A strong passcode increases the difficulty of brute-forcing access to the hardware encryption key.
Lock the App:
Signal offers an additional layer of security with its in-app locking feature (e.g., requiring Face ID or a passcode to open the app).
Conclusion
Signal on an Apple mobile device relies on the first boot state and the device's robust encryption architecture to protect user data. If the device has not been unlocked since power-on, even advanced forensic tools like Cellebrite cannot access Signal messages. After the first unlock, Signal's additional encryption and iOS's data protection still provide strong safeguards against unauthorized access.
4o
You said:
so the current plan for our messaging protocol keeps messages encrypted until decoded on demand, there is a salt added to the AES 256 encryption key the salt is either derived from a key phase entered by the user, maybe stored on a server or pehaps somehow derived from a biomentric not sure of the best method yet but we don't the messages to be vulneralbe if someone gets hold of the decryption key its a prime requirement we are still working out
ChatGPT said:
ChatGPT
Memory updated
Your plan for using a salted AES-256 key is robust and aligns with good cryptographic practices. Here are some considerations to refine the salt generation and storage approach:
1. Salt Derivation Options
a. User-Entered Key Phrase
Advantages:
Adds a personal element to the encryption, ensuring the salt is unique per user.
If kept secret by the user, it's difficult for attackers to obtain.
Disadvantages:
Relies on the user's ability to remember the key phrase.
Susceptible to weak phrases if not enforced with strict password policies.
Enhancements:
Use a key derivation function (KDF) like PBKDF2, bcrypt, or Argon2 to derive a strong salt from the key phrase.
b. Server-Stored Value
Advantages:
Centralized control of salt values simplifies management.
Easier to ensure uniqueness and avoid reuse.
Disadvantages:
Introduces a dependency on the server's security.
If the server is compromised, salts could be exposed.
Enhancements:
Store salts separately from encrypted data and ensure server-side encryption for salt storage.
c. Biometric-Derived Salt
Advantages:
Provides a convenient and user-friendly way to generate unique salts.
Can leverage hardware security features (e.g., Secure Enclave or Trusted Platform Module).
Disadvantages:
Biometric data cannot be changed if compromised.
Requires additional processing to derive a cryptographically strong salt from the biometric input.
Enhancements:
Use a one-way hash function to convert biometric data into a salt without storing raw biometric values.
2. Security Considerations
a. Protection Against Key and Salt Exposure
Combine the salt with a device-specific identifier (e.g., a hardware UUID) to prevent use on another device.
Encrypt the salt itself using a secondary key or secure hardware module.
b. Forward Secrecy
Use a mechanism to periodically rotate the salt or keys.
Store previous salts securely for decrypting older messages if needed.
c. Salt Uniqueness
Ensure the salt is unique per user or session to avoid reuse attacks.
d. Decentralized Derivation
A combination of user-entered phrases and device-specific or biometric factors can remove reliance on centralized servers, enhancing security.
3. Recommendations
Primary Option: Combine a user-entered key phrase with a device-specific factor and a server-stored component. Use a KDF to derive a final salt from these inputs.
Backup Option: Use biometrics with a secure hashing mechanism for situations where user convenience is paramount, ensuring fallback mechanisms are in place.
This approach will give you flexibility while meeting your prime requirement of safeguarding messages even if a single decryption key is compromised. Let me know if you'd like help refining specific aspects of the protocol!
4o
You said:
Cellebrite vulnerability to each recommendation
ChatGPT said:
ChatGPT
Cellebrite's forensic tools are designed to extract data from mobile devices, often used by law enforcement agencies. Understanding how your proposed encryption methods interact with such tools is crucial for maintaining data security. Here's an analysis of each recommendation in relation to potential vulnerabilities to Cellebrite's extraction capabilities:
1. User-Entered Key Phrase Combined with Device-Specific Factor and Server-Stored Component
Cellebrite's Capabilities:
If the device is unlocked and accessible, Cellebrite can extract data stored on the device.
However, if the encryption key is derived from a user-entered passphrase combined with device-specific factors and a server-stored component, and this key is not stored on the device, Cellebrite would not have access to the decryption key.
Vulnerability Assessment:
Low: As long as the decryption key is not stored on the device and requires user input or server communication, Cellebrite's tools cannot decrypt the data without access to all components of the key derivation process.
Mitigation Strategies:
Ensure that the user-entered passphrase is strong and not stored on the device.
Secure the server-stored component to prevent unauthorized access.
Implement device-specific factors that are not easily extractable.
2. Biometrics with Secure Hashing Mechanism
Cellebrite's Capabilities:
Cellebrite can extract biometric data stored on the device if it is accessible.
If the biometric data is used directly for encryption without additional factors, and Cellebrite can extract this data, they may attempt to use it to decrypt the information.
Vulnerability Assessment:
Moderate: Biometric data alone may be vulnerable if extracted. However, if combined with other factors (e.g., device-specific identifiers or user passphrases), the security is enhanced.
Mitigation Strategies:
Combine biometric data with other factors to derive the encryption key.
Ensure that biometric data is stored securely and not in a form that can be easily extracted or replicated.
Use secure hashing mechanisms to process biometric data before using it in key derivation.
3. Periodic Rotation of Salt or Keys
Cellebrite's Capabilities:
Cellebrite can extract data present on the device at the time of extraction.
If salts or keys are rotated and old keys are securely deleted, previously encrypted data becomes inaccessible without the old keys.
Vulnerability Assessment:
Low: Regular rotation of keys or salts, combined with secure deletion of old keys, limits the amount of data vulnerable to extraction at any given time.
Mitigation Strategies:
Implement a secure key management system that handles key rotation and deletion.
Ensure that old keys are irrecoverably deleted from the device.
Maintain secure backups of keys if necessary, stored separately from the device.
4. Decentralized Derivation Combining User Passphrase, Device-Specific, and Biometric Factors
Cellebrite's Capabilities:
Cellebrite can extract data stored on the device, including any device-specific identifiers and potentially biometric data.
Without the user passphrase, they would not have all components needed to derive the decryption key.
Vulnerability Assessment:
Low: By decentralizing the key derivation process and requiring multiple factors, the security is enhanced. Even if Cellebrite extracts some components, they would not have the complete key without user input.
Mitigation Strategies:
Ensure that the user passphrase is strong and not stored on the device.
Protect device-specific identifiers and biometric data from unauthorized access.
Use secure methods to combine these factors into a single encryption key.
General Recommendations:
Device Locking: Encourage users to keep their devices locked when not in use. An unlocked device is more vulnerable to data extraction.
Secure Storage: Avoid storing sensitive components (e.g., user passphrases, decryption keys) directly on the device.
User Education: Educate users on the importance of strong passphrases and the risks of leaving devices unlocked.
By implementing these strategies, you can enhance the security of your messaging protocol against potential extraction attempts by tools like Cellebrite.