Monday, January 26, 2026

Privacy-Preserving Federated Learning Architectures for Distributed IoT Networks: Implementing Zero-Knowledge Protocols with aéPiot Coordination - PART 2

 

for round_num in range(num_rounds):
            print(f"\n=== Federated Round {round_num + 1}/{num_rounds} ===")
            
            # 1. Broadcast global model to all participants
            await self.broadcast_global_model()
            
            # 2. Each participant trains locally
            local_updates = await self.local_training_phase(local_epochs)
            
            # 3. Secure aggregation with privacy preservation
            aggregated_update = await self.privacy_preserving_aggregation(local_updates)
            
            # 4. Update global model
            self.global_model = self.apply_update(
                self.global_model,
                aggregated_update['update']
            )
            
            # 5. Evaluate global model
            global_performance = await self.evaluate_global_model()
            
            # 6. Log round via aéPiot
            round_record = await self.log_training_round(
                round_num,
                global_performance,
                aggregated_update['privacy_record']
            )
            
            training_history.append({
                'round': round_num,
                'performance': global_performance,
                'privacy_record': round_record
            })
            
            print(f"Round {round_num + 1} complete. Accuracy: {global_performance['accuracy']:.4f}")
        
        return training_history
    
    async def broadcast_global_model(self):
        """
        Distribute current global model to all participants via aéPiot
        """
        
        # Serialize model
        model_weights = self.global_model.get_weights()
        
        # Create aéPiot distribution record
        distribution_subdomains = await self.aepiot_coordinator.aepiotServices.randomSubdomain.generate({
            'count': 3,
            'purpose': 'model_distribution'
        })
        
        # Distribute to each participant
        for participant in self.participants:
            await participant.receive_global_model(model_weights, distribution_subdomains)
    
    async def local_training_phase(self, local_epochs):
        """
        Each participant trains on their local data
        """
        
        local_updates = []
        
        # Parallel local training
        training_tasks = [
            participant.train_locally(self.global_model, local_epochs)
            for participant in self.participants
        ]
        
        local_updates = await asyncio.gather(*training_tasks)
        
        return local_updates
    
    async def privacy_preserving_aggregation(self, local_updates):
        """
        Aggregate local updates with multiple privacy techniques
        """
        
        # Extract gradients from updates
        gradients = [update['gradients'] for update in local_updates]
        
        # Step 1: Differential Privacy (clip + noise)
        dp_result = await self.differential_privacy.private_gradient_aggregation(
            [{'compute_gradients': lambda: g} for g in gradients]
        )
        
        # Step 2: Homomorphic Encryption (optional, for additional security)
        # he_aggregator = HomomorphicFederatedAggregation(scheme='CKKS')
        # he_result = await he_aggregator.federated_round_with_he(participants)
        
        # Step 3: Secure Multi-Party Computation
        smpc_result = await self.secure_aggregation.secure_federated_aggregation(
            [{'compute_gradient': lambda: dp_result['noisy_gradients']}] * len(self.participants)
        )
        
        # Create comprehensive privacy audit via aéPiot
        privacy_audit = await self.create_privacy_audit({
            'differential_privacy': dp_result['privacy_record'],
            'secure_mpc': smpc_result['aggregation_record'],
            'privacy_guarantee': dp_result['privacy_guarantee']
        })
        
        return {
            'update': smpc_result['aggregated_gradient'],
            'privacy_record': privacy_audit
        }
    
    async def create_privacy_audit(self, privacy_components):
        """
        Create comprehensive privacy audit trail via aéPiot
        """
        
        audit_description = (
            f"Privacy-preserving aggregation completed. "
            f"Techniques: Differential Privacy {privacy_components['privacy_guarantee']}, "
            f"Secure Multi-Party Computation (Shamir Secret Sharing)"
        )
        
        audit_record = await self.aepiot_coordinator.aepiotServices.backlink.create({
            'title': 'Privacy-Preserving Aggregation Audit',
            'description': audit_description,
            'link': f'privacy-audit://{int(time.time())}'
        })
        
        return audit_record

3.3 Vertical Federated Learning with aéPiot

Challenge: Different features require different aggregation strategy

Implementation:

python
class VerticalFederatedLearning:
    """
    Vertical FL: Different features across participants
    Example: Bank + Hospital collaborate on fraud/health prediction
    """
    
    def __init__(self):
        self.aepiot_coordinator = AePiotFederatedCoordinator()
        self.participants = {}  # {participant_id: feature_columns}
        
        # Privacy techniques
        self.homomorphic_encryption = HomomorphicFederatedAggregation(scheme='CKKS')
        self.secure_mpc = SecureMultiPartyAggregation(threshold=2, num_parties=0)
    
    async def register_participant_with_features(self, participant_id, feature_columns):
        """
        Register participant and their feature space
        """
        
        self.participants[participant_id] = feature_columns
        
        # Create aéPiot registration with feature metadata
        registration_record = await self.aepiot_coordinator.aepiotServices.backlink.create({
            'title': f'VFL Participant - {participant_id}',
            'description': f'Participant {participant_id} with features: {", ".join(feature_columns)}',
            'link': f'vfl-participant://{participant_id}'
        })
        
        return registration_record
    
    async def vertical_training_round(self):
        """
        Training round for vertical federated learning
        """
        
        # 1. Each participant computes embeddings for their features
        embeddings = {}
        for participant_id, features in self.participants.items():
            # Participant computes local embedding using their features
            local_embedding = await self.compute_local_embedding(participant_id, features)
            
            # Encrypt embedding
            encrypted_embedding = await self.homomorphic_encryption.encrypt_gradients(
                local_embedding
            )
            
            embeddings[participant_id] = encrypted_embedding
        
        # 2. Securely aggregate embeddings (still encrypted)
        encrypted_embeddings_list = list(embeddings.values())
        aggregated_encrypted = await self.homomorphic_encryption.aggregate_encrypted_gradients(
            [e['encrypted_gradients'] for e in encrypted_embeddings_list]
        )
        
        # 3. Compute loss on aggregated embedding (in encrypted space)
        # Only one participant (or secure enclave) decrypts for final prediction
        
        # 4. Backpropagate gradients to each participant's features
        # Each participant only receives gradients for their features
        
        # 5. Create aéPiot audit record
        vfl_record = await self.aepiot_coordinator.aepiotServices.backlink.create({
            'title': 'Vertical FL Training Round',
            'description': f'Aggregated embeddings from {len(self.participants)} participants with HE',
            'link': f'vfl-round://{int(time.time())}'
        })
        
        return {
            'aggregated_encrypted': aggregated_encrypted,
            'audit_record': vfl_record
        }
    
    async def private_set_intersection(self, participant_a, participant_b):
        """
        Find common samples between participants without revealing non-overlapping samples
        Uses Private Set Intersection (PSI) protocol
        """
        
        # PSI protocol ensures:
        # - Participants learn only intersection
        # - Non-overlapping IDs remain private
        
        from openmined.psi import client, server
        
        # Participant A acts as server
        psi_server = server.CreateWithNewKey()
        server_setup = psi_server.CreateSetupMessage(
            fpr=1e-9,  # False positive rate
            num_client_inputs=len(participant_b.sample_ids),
            inputs=participant_a.sample_ids
        )
        
        # Participant B acts as client
        psi_client = client.CreateWithNewKey()
        client_request = psi_client.CreateRequest(participant_b.sample_ids)
        
        # Server processes request
        server_response = psi_server.ProcessRequest(client_request)
        
        # Client computes intersection
        intersection = psi_client.GetIntersection(server_setup, server_response)
        
        # Create aéPiot PSI record
        psi_record = await self.aepiot_coordinator.aepiotServices.backlink.create({
            'title': 'Private Set Intersection',
            'description': f'Found {len(intersection)} common samples between participants',
            'link': f'psi://{participant_a.id}/{participant_b.id}/{int(time.time())}'
        })
        
        return {
            'intersection': intersection,
            'psi_record': psi_record
        }

3.4 Communication-Efficient Federated Learning

Challenge: Gradient transmission is expensive (bandwidth, latency)

Solutions:

1. Gradient Compression

python
class GradientCompression:
    """
    Reduce gradient size for efficient transmission
    """
    
    def __init__(self, compression_ratio=0.01):
        self.compression_ratio = compression_ratio
        self.aepiot_semantic = AePiotSemanticProcessor()
    
    def top_k_sparsification(self, gradients, k_ratio):
        """
        Keep only top-k largest gradients by magnitude
        """
        
        # Flatten gradients
        flat_gradients = gradients.flatten()
        
        # Calculate k
        k = int(len(flat_gradients) * k_ratio)
        
        # Get indices of top-k by absolute value
        top_k_indices = np.argpartition(np.abs(flat_gradients), -k)[-k:]
        
        # Create sparse representation
        sparse_gradients = {
            'indices': top_k_indices,
            'values': flat_gradients[top_k_indices],
            'shape': gradients.shape
        }
        
        # Compression ratio achieved
        original_size = gradients.nbytes
        compressed_size = (top_k_indices.nbytes + 
                          sparse_gradients['values'].nbytes)
        actual_compression = compressed_size / original_size
        
        return sparse_gradients, actual_compression
    
    def gradient_quantization(self, gradients, num_bits=8):
        """
        Quantize gradients to reduce precision
        32-bit float → 8-bit int = 75% size reduction
        """
        
        # Find min and max
        min_val = np.min(gradients)
        max_val = np.max(gradients)
        
        # Quantization levels
        num_levels = 2 ** num_bits
        
        # Scale to [0, num_levels-1]
        scaled = (gradients - min_val) / (max_val - min_val) * (num_levels - 1)
        
        # Quantize
        quantized = np.round(scaled).astype(f'uint{num_bits}')
        
        return {
            'quantized': quantized,
            'min': min_val,
            'max': max_val,
            'num_bits': num_bits
        }
    
    def dequantize(self, quantized_data):
        """
        Reconstruct gradients from quantized representation
        """
        
        num_levels = 2 ** quantized_data['num_bits']
        
        # Descale
        descaled = (quantized_data['quantized'].astype(np.float32) / (num_levels - 1))
        
        # Denormalize
        gradients = (descaled * (quantized_data['max'] - quantized_data['min']) + 
                    quantized_data['min'])
        
        return gradients
    
    async def compress_and_transmit(self, gradients):
        """
        Compress gradients before transmission
        """
        
        # Apply both sparsification and quantization
        sparse, sparsity_ratio = self.top_k_sparsification(
            gradients,
            k_ratio=self.compression_ratio
        )
        
        quantized = self.gradient_quantization(
            sparse['values'],
            num_bits=8
        )
        
        compressed = {
            'indices': sparse['indices'],
            'quantized_values': quantized,
            'shape': sparse['shape']
        }
        
        # Calculate total compression
        original_size = gradients.nbytes
        compressed_size = (compressed['indices'].nbytes + 
                          compressed['quantized_values']['quantized'].nbytes)
        total_compression = compressed_size / original_size
        
        # Create aéPiot compression record
        compression_record = await self.aepiot_semantic.createBacklink({
            'title': 'Gradient Compression',
            'description': f'Compressed gradients: {total_compression:.2%} of original size',
            'link': f'compression://{int(time.time())}'
        })
        
        return {
            'compressed': compressed,
            'compression_ratio': total_compression,
            'record': compression_record
        }

2. Federated Averaging Variants

python
class FederatedOptimizationAlgorithms:
    """
    Advanced federated optimization algorithms
    """
    
    def __init__(self):
        self.aepiot_coordinator = AePiotFederatedCoordinator()
    
    async def fedavg(self, local_updates, participant_data_sizes):
        """
        Federated Averaging (FedAvg) - Original FL algorithm
        Weighted average based on local dataset size
        """
        
        total_data_size = sum(participant_data_sizes)
        
        # Weighted average
        aggregated = np.zeros_like(local_updates[0])
        for update, data_size in zip(local_updates, participant_data_sizes):
            weight = data_size / total_data_size
            aggregated += weight * update
        
        return aggregated
    
    async def fedprox(self, local_updates, participant_data_sizes, mu=0.01):
        """
        Federated Proximal (FedProx) - Handles heterogeneous data
        Adds proximal term to keep local models close to global
        """
        
        # Similar to FedAvg but with proximal regularization
        # Local objective: F_i(w) + (μ/2)||w - w_global||^2
        
        aggregated = await self.fedavg(local_updates, participant_data_sizes)
        
        # Proximal term is applied during local training
        # This aggregation step remains same as FedAvg
        
        return aggregated
    
    async def fedopt(self, local_updates, global_optimizer='adam'):
        """
        Federated Optimization (FedOpt) - Use server-side optimizer
        Apply Adam/SGD on server for better convergence
        """
        
        # Aggregate updates (uniform average)
        aggregated = np.mean(local_updates, axis=0)
        
        # Apply server-side optimizer
        if global_optimizer == 'adam':
            # Adam optimizer on server
            optimized_update = self.server_adam_step(aggregated)
        elif global_optimizer == 'sgd':
            optimized_update = aggregated  # Standard SGD
        
        return optimized_update
    
    async def scaffold(self, local_updates, control_variates):
        """
        SCAFFOLD - Uses control variates to reduce client drift
        Particularly effective for non-IID data
        """
        
        # Control variates track difference between local and global updates
        # Corrects for heterogeneous data distribution
        
        corrected_updates = []
        for update, control_variate in zip(local_updates, control_variates):
            corrected = update - control_variate
            corrected_updates.append(corrected)
        
        aggregated = np.mean(corrected_updates, axis=0)
        
        return aggregated

3.5 Byzantine-Resilient Aggregation

Challenge: Malicious participants send corrupted updates to poison model

Solutions:

python
class ByzantineResilientAggregation:
    """
    Defend against Byzantine (malicious) participants
    """
    
    def __init__(self, byzantine_ratio=0.2):
        self.byzantine_ratio = byzantine_ratio
        self.aepiot_coordinator = AePiotFederatedCoordinator()
    
    async def krum(self, updates, num_byzantine):
        """
        Krum aggregation - Select most representative update
        Robust to Byzantine attacks
        """
        
        n = len(updates)
        f = num_byzantine
        
        # Calculate pairwise distances
        distances = np.zeros((n, n))
        for i in range(n):
            for j in range(n):
                if i != j:
                    distances[i, j] = np.linalg.norm(updates[i] - updates[j])
        
        # For each update, sum distances to (n-f-2) closest neighbors
        scores = []
        for i in range(n):
            sorted_distances = np.sort(distances[i])
            score = np.sum(sorted_distances[:n-f-2])
            scores.append(score)
        
        # Select update with minimum score (most representative)
        krum_index = np.argmin(scores)
        selected_update = updates[krum_index]
        
        # Create aéPiot audit record
        krum_record = await self.aepiot_coordinator.aepiotServices.backlink.create({
            'title': 'Krum Byzantine-Resilient Aggregation',
            'description': f'Selected update {krum_index} as most representative from {n} participants',
            'link': f'krum-aggregate://{int(time.time())}'
        })
        
        return {
            'aggregated': selected_update,
            'selected_index': krum_index,
            'audit_record': krum_record
        }
    
    async def trimmed_mean(self, updates, trim_ratio=0.2):
        """
        Trimmed Mean - Remove outliers before averaging
        Robust to Byzantine attacks
        """
        
        # Sort updates along each dimension
        stacked = np.stack(updates)
        
        # Calculate number to trim from each end
        num_trim = int(len(updates) * trim_ratio)
        
        # Trimmed mean along participant dimension
        sorted_updates = np.sort(stacked, axis=0)
        trimmed = sorted_updates[num_trim:-num_trim] if num_trim > 0 else sorted_updates
        aggregated = np.mean(trimmed, axis=0)
        
        # Create aéPiot audit record
        trim_record = await self.aepiot_coordinator.aepiotServices.backlink.create({
            'title': 'Trimmed Mean Aggregation',
            'description': f'Trimmed {num_trim} outliers from each end before averaging',
            'link': f'trimmed-mean://{int(time.time())}'
        })
        
        return {
            'aggregated': aggregated,
            'num_trimmed': num_trim,
            'audit_record': trim_record
        }
    
    async def median_aggregation(self, updates):
        """
        Coordinate-wise Median - Most robust but computationally expensive
        """
        
        stacked = np.stack(updates)
        aggregated = np.median(stacked, axis=0)
        
        # Create aéPiot audit record
        median_record = await self.aepiot_coordinator.aepiotServices.backlink.create({
            'title': 'Median Aggregation',
            'description': f'Coordinate-wise median of {len(updates)} updates',
            'link': f'median-aggregate://{int(time.time())}'
        })
        
        return {
            'aggregated': aggregated,
            'audit_record': median_record
        }

Part 4: Zero-Knowledge Protocol Implementation

4. Advanced Zero-Knowledge Systems for Federated Learning

4.1 zk-SNARKs for Gradient Verification

Use Case: Prove gradient computation correctness without revealing training data

Complete Implementation:

python
class ZKSNARKGradientVerification:
    """
    Production-ready zk-SNARK system for gradient verification
    Based on Groth16 proof system
    """
    
    def __init__(self):
        self.aepiot_semantic = AePiotSemanticProcessor()
        
        # Circuit compilation
        self.circuit = self.compile_gradient_circuit()
        
        # Trusted setup (in production: use MPC ceremony)
        self.proving_key, self.verification_key = self.trusted_setup_ceremony()
    
    def compile_gradient_circuit(self):
        """
        Compile gradient computation into arithmetic circuit
        Circuit represents: gradient = ∂L/∂w for loss L and weights w
        """
        
        from zokrates_pycrypto import compile_program
        
        # ZoKrates code for gradient verification
        circuit_code = """
        // Verify gradient computation correctness
        
        def main(private field[10] data, private field[10] weights, 
                 public field[10] gradient_commitment) -> bool:
            
            // Compute forward pass
            field prediction = 0
            for u32 i in 0..10:
                prediction = prediction + data[i] * weights[i]
            endfor
            
            // Compute loss (simplified MSE)
            field loss = (prediction - 1) * (prediction - 1)
            
            // Compute gradients
            field[10] mut computed_gradients = [0; 10]
            for u32 i in 0..10:
                computed_gradients[i] = 2 * (prediction - 1) * data[i]
            endfor
            
            // Verify gradient commitment
            field gradient_hash = hash(computed_gradients)
            
            return gradient_hash == gradient_commitment[0]
        """
        
        # Compile to R1CS (Rank-1 Constraint System)
        compiled_circuit = compile_program(circuit_code)
        
        return compiled_circuit
    
    def trusted_setup_ceremony(self):
        """
        Trusted setup using multi-party computation
        Ensures no single party knows toxic waste
        """
        
        from zksnark import setup
        
        # In production: Use Powers of Tau ceremony with multiple participants
        # Each participant contributes randomness
        # As long as one participant is honest, setup is secure
        
        proving_key, verification_key = setup(self.circuit)
        
        return proving_key, verification_key
    
    async def prove_gradient_correctness(self, training_data, weights, gradients):
        """
        Generate ZK proof that gradients were computed correctly
        """
        
        # Prepare witness (private inputs)
        witness = {
            'data': training_data,
            'weights': weights,
            'computed_gradients': gradients
        }
        
        # Compute gradient commitment (public input)
        gradient_commitment = self.hash_gradients(gradients)
        
        public_inputs = {
            'gradient_commitment': gradient_commitment
        }
        
        # Generate proof
        start_time = time.time()
        proof = self.generate_proof(
            circuit=self.circuit,
            proving_key=self.proving_key,
            witness=witness,
            public_inputs=public_inputs
        )
        proof_time = time.time() - start_time
        
        # Create aéPiot proof record
        proof_record = await self.aepiot_semantic.createBacklink({
            'title': 'zk-SNARK Gradient Proof',
            'description': f'Proof generated in {proof_time:.3f}s. Proof size: {len(proof)} bytes',
            'link': f'zksnark-proof://{self.hash(proof)}'
        })
        
        return {
            'proof': proof,
            'public_inputs': public_inputs,
            'proof_size_bytes': len(proof),
            'proving_time_seconds': proof_time,
            'proof_record': proof_record
        }
    
    async def verify_gradient_proof(self, proof, public_inputs):
        """
        Verify ZK proof (fast: ~milliseconds)
        """
        
        start_time = time.time()
        is_valid = self.zksnark_verify(
            verification_key=self.verification_key,
            proof=proof,
            public_inputs=public_inputs
        )
        verification_time = time.time() - start_time
        
        # Create aéPiot verification record
        verification_record = await self.aepiot_semantic.createBacklink({
            'title': 'zk-SNARK Verification',
            'description': f'Verification result: {is_valid}. Time: {verification_time*1000:.2f}ms',
            'link': f'zksnark-verify://{self.hash(proof)}/{int(time.time())}'
        })
        
        return {
            'valid': is_valid,
            'verification_time_seconds': verification_time,
            'verification_record': verification_record
        }
    
    async def federated_round_with_zk_verification(self, participants):
        """
        Federated learning round where each gradient is ZK-verified
        """
        
        verified_gradients = []
        verification_records = []
        
        for participant in participants:
            # Participant computes gradients
            gradients = participant.compute_gradients()
            
            # Participant generates ZK proof
            proof_result = await self.prove_gradient_correctness(
                training_data=participant.local_data,
                weights=participant.local_weights,
                gradients=gradients
            )
            
            # Aggregator verifies proof
            verification_result = await self.verify_gradient_proof(
                proof=proof_result['proof'],
                public_inputs=proof_result['public_inputs']
            )
            
            if verification_result['valid']:
                verified_gradients.append(gradients)
                verification_records.append(verification_result['verification_record'])
            else:
                print(f"Warning: Participant {participant.id} submitted invalid proof")
        
        # Aggregate only verified gradients
        if verified_gradients:
            aggregated = np.mean(verified_gradients, axis=0)
            
            # Create aéPiot aggregation record
            agg_record = await self.aepiot_semantic.createBacklink({
                'title': 'ZK-Verified Aggregation',
                'description': f'Aggregated {len(verified_gradients)} ZK-verified gradients',
                'link': f'zk-aggregate://{int(time.time())}'
            })
            
            return {
                'aggregated_gradients': aggregated,
                'num_verified': len(verified_gradients),
                'verification_records': verification_records,
                'aggregation_record': agg_record
            }
        else:
            raise ValueError("No valid gradients received")

4.2 Zero-Knowledge Range Proofs

Use Case: Prove gradients are within acceptable bounds without revealing exact values

python
class ZeroKnowledgeRangeProof:
    """
    Bulletproofs for range proofs
    Prove that gradient values are in acceptable range
    """
    
    def __init__(self, min_value=-10.0, max_value=10.0):
        self.min_value = min_value
        self.max_value = max_value
        self.aepiot_semantic = AePiotSemanticProcessor()
    
    def generate_range_proof(self, value, min_val, max_val):
        """
        Generate Bulletproof that value ∈ [min_val, max_val]
        """
        
        from bulletproofs import RangeProof
        
        # Convert to integer range (scale float)
        scale = 1000
        value_int = int(value * scale)
        min_int = int(min_val * scale)
        max_int = int(max_val * scale)
        
        # Shift to positive range [0, max_int - min_int]
        shifted_value = value_int - min_int
        range_size = max_int - min_int
        
        # Generate Bulletproof
        proof = RangeProof.prove(
            value=shifted_value,
            min=0,
            max=range_size,
            blinding_factor=self.generate_random_blinding()
        )
        
        return proof
    
    async def prove_gradient_in_range(self, gradients):
        """
        Prove all gradient components are within acceptable range
        """
        
        proofs = []
        
        for gradient_value in gradients.flatten():
            proof = self.generate_range_proof(
                gradient_value,
                self.min_value,
                self.max_value
            )
            proofs.append(proof)
        
        # Aggregate proofs (Bulletproofs are logarithmic in size)
        aggregated_proof = self.aggregate_bulletproofs(proofs)
        
        # Create aéPiot proof record
        range_proof_record = await self.aepiot_semantic.createBacklink({
            'title': 'Gradient Range Proof',
            'description': f'Proved {len(gradients.flatten())} gradients in range [{self.min_value}, {self.max_value}]',
            'link': f'range-proof://{int(time.time())}'
        })
        
        return {
            'proof': aggregated_proof,
            'num_gradients': len(gradients.flatten()),
            'range': [self.min_value, self.max_value],
            'proof_record': range_proof_record
        }
    
    def verify_range_proof(self, proof):
        """
        Verify range proof (logarithmic verification time)
        """
        
        from bulletproofs import RangeProof
        
        is_valid = RangeProof.verify(proof)
        
        return is_valid
    
    async def gradient_clipping_with_zk_proof(self, gradients):
        """
        Clip gradients and prove they're within bounds using ZK
        """
        
        # Clip gradients
        clipped = np.clip(gradients, self.min_value, self.max_value)
        
        # Generate range proof
        range_proof_result = await self.prove_gradient_in_range(clipped)
        
        return {
            'clipped_gradients': clipped,
            'range_proof': range_proof_result['proof'],
            'proof_record': range_proof_result['proof_record']
        }

4.3 Verifiable Computation with Trusted Execution Environments

Use Case: Hardware-based trusted computation for aggregation

python
class TEEFederatedAggregation:
    """
    Use Intel SGX or ARM TrustZone for trusted aggregation
    """
    
    def __init__(self, tee_type='sgx'):
        self.tee_type = tee_type
        self.aepiot_semantic = AePiotSemanticProcessor()
        
        # Initialize TEE enclave
        self.enclave = self.initialize_enclave()
    
    def initialize_enclave(self):
        """
        Initialize Trusted Execution Environment enclave
        """
        
        if self.tee_type == 'sgx':
            # Intel SGX initialization
            from sgx import Enclave
            
            enclave = Enclave(
                enclave_path='./aggregation_enclave.so',
                config_path='./enclave_config.xml'
            )
            
            return enclave
        
        elif self.tee_type == 'trustzone':
            # ARM TrustZone initialization
            from trustzone import SecureWorld
            
            secure_world = SecureWorld()
            return secure_world
    
    async def remote_attestation(self):
        """
        Prove enclave is running genuine code on genuine hardware
        """
        
        # Generate attestation quote
        quote = self.enclave.generate_quote()
        
        # Remote attestation with Intel Attestation Service (IAS)
        attestation_result = await self.verify_with_ias(quote)
        
        # Create aéPiot attestation record
        attestation_record = await self.aepiot_semantic.createBacklink({
            'title': 'TEE Remote Attestation',
            'description': f'Attestation successful. Enclave verified as genuine.',
            'link': f'tee-attestation://{int(time.time())}'
        })
        
        return {
            'attestation_valid': attestation_result['valid'],
            'enclave_measurement': attestation_result['mrenclave'],
            'attestation_record': attestation_record
        }
    
    async def tee_secure_aggregation(self, encrypted_gradients):
        """
        Aggregate gradients inside TEE enclave
        """
        
        # 1. Remote attestation proves enclave is genuine
        attestation = await self.remote_attestation()
        
        if not attestation['attestation_valid']:
            raise SecurityError("TEE attestation failed")
        
        # 2. Participants send encrypted gradients to enclave
        # Only enclave can decrypt (keys sealed to enclave)
        
        # 3. Enclave decrypts and aggregates inside protected memory
        aggregated = self.enclave.secure_aggregate(encrypted_gradients)
        
        # 4. Enclave re-encrypts result for distribution
        encrypted_result = self.enclave.encrypt_output(aggregated)
        
        # 5. Create aéPiot TEE aggregation record
        tee_record = await self.aepiot_semantic.createBacklink({
            'title': 'TEE Secure Aggregation',
            'description': f'Aggregated {len(encrypted_gradients)} gradients in SGX enclave',
            'link': f'tee-aggregate://{int(time.time())}'
        })
        
        return {
            'encrypted_aggregated': encrypted_result,
            'enclave_measurement': attestation['enclave_measurement'],
            'tee_record': tee_record
        }
    
    def enclave_code_example(self):
        """
        Example of code running inside SGX enclave
        This code has access to decrypted gradients but is isolated
        """
        
        enclave_c_code = """
        // This code runs inside SGX enclave
        // Has access to decrypted data in protected memory
        
        #include <sgx_tcrypto.h>
        
        sgx_status_t ecall_aggregate_gradients(
            const uint8_t* encrypted_gradients,
            size_t num_gradients,
            uint8_t* encrypted_result
        ) {
            // Decrypt gradients inside enclave
            float* gradients = decrypt_inside_enclave(encrypted_gradients, num_gradients);
            
            // Aggregate (code verified by attestation)
            float* aggregated = aggregate(gradients, num_gradients);
            
            // Re-encrypt result
            encrypt_inside_enclave(aggregated, encrypted_result);
            
            // Securely erase decrypted data
            memset_s(gradients, 0, sizeof(float) * num_gradients);
            
            return SGX_SUCCESS;
        }
        """
        
        return enclave_c_code

4.4 Zero-Knowledge Machine Learning (ZKML)

Cutting-Edge: Prove entire ML model execution using ZK

python
class ZeroKnowledgeMachineLearning:
    """
    ZKML: Prove ML inference/training without revealing model or data
    Extremely advanced - requires specialized ZK frameworks
    """
    
    def __init__(self):
        self.aepiot_semantic = AePiotSemanticProcessor()
    
    async def prove_model_inference(self, model, input_data, predicted_output):
        """
        Generate ZK proof that: output = model(input)
        Without revealing model weights or input data
        """
        
        # Convert ML model to arithmetic circuit
        # This is extremely complex for deep neural networks
        circuit = self.convert_model_to_circuit(model)
        
        # Witness: model weights + input data + intermediate activations
        witness = {
            'weights': model.get_weights(),
            'input': input_data,
            'activations': self.compute_all_activations(model, input_data)
        }
        
        # Public input: only the predicted output
        public_inputs = {
            'output': predicted_output
        }
        
        # Generate proof (very computationally expensive)
        proof = self.generate_zkml_proof(circuit, witness, public_inputs)
        
        # Create aéPiot ZKML record
        zkml_record = await self.aepiot_semantic.createBacklink({
            'title': 'ZKML Inference Proof',
            'description': f'Proved model inference without revealing weights or input',
            'link': f'zkml://{int(time.time())}'
        })
        
        return {
            'proof': proof,
            'zkml_record': zkml_record
        }

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