# Security & Performance Optimization 2025

## 🔐 1. Zero Trust Architecture (NIST SP 1800-35)

### Core Principles
1. **Never Trust, Always Verify**
2. **Assume Breach**
3. **Verify Explicitly**
4. **Secure Every Path**

### Implementation for TraceRTM

```go
// backend/internal/auth/zero_trust.go
type ZeroTrustMiddleware struct {
    authService *AuthService
    auditLog    *AuditLog
}

func (ztm *ZeroTrustMiddleware) Verify(c echo.Context) error {
    // 1. Verify identity
    token := c.Request().Header.Get("Authorization")
    user, err := ztm.authService.VerifyToken(token)
    if err != nil {
        ztm.auditLog.LogFailedAuth(c.Request())
        return echo.NewHTTPError(401, "Unauthorized")
    }
    
    // 2. Verify device
    deviceId := c.Request().Header.Get("X-Device-ID")
    if !ztm.authService.IsDeviceTrusted(user.ID, deviceId) {
        ztm.auditLog.LogUntrustedDevice(user.ID, deviceId)
        return echo.NewHTTPError(403, "Device not trusted")
    }
    
    // 3. Verify context
    if !ztm.authService.IsContextValid(user, c.Request()) {
        ztm.auditLog.LogSuspiciousActivity(user.ID, c.Request())
        return echo.NewHTTPError(403, "Context invalid")
    }
    
    // 4. Verify permissions
    resource := c.Param("id")
    if !ztm.authService.HasPermission(user, resource, c.Request().Method) {
        ztm.auditLog.LogUnauthorizedAccess(user.ID, resource)
        return echo.NewHTTPError(403, "Forbidden")
    }
    
    return nil
}
```

### ABAC (Attribute-Based Access Control) with OPA

```rego
# infrastructure/opa/policies.rego
package tracertm

default allow = false

allow {
    input.user.role == "admin"
}

allow {
    input.user.role == "editor"
    input.resource.owner == input.user.id
}

allow {
    input.user.role == "viewer"
    input.resource.public == true
}

allow {
    input.user.role == "editor"
    input.resource.project_id == input.user.project_id
    input.action == "read"
}
```

## ⚡ 2. Performance Optimization (2025)

### Caching Strategy

```go
// backend/internal/cache/multi_level.go
type MultiLevelCache struct {
    l1 *LocalCache      // In-memory
    l2 *RedisCache      // Distributed
    db *PostgresDB      // Source of truth
}

func (mlc *MultiLevelCache) Get(ctx context.Context, key string) (interface{}, error) {
    // L1: Check local cache
    if val, ok := mlc.l1.Get(key); ok {
        return val, nil
    }
    
    // L2: Check Redis
    val, err := mlc.l2.Get(ctx, key)
    if err == nil {
        mlc.l1.Set(key, val)
        return val, nil
    }
    
    // L3: Query database
    val, err = mlc.db.Get(ctx, key)
    if err != nil {
        return nil, err
    }
    
    // Populate caches
    mlc.l2.Set(ctx, key, val)
    mlc.l1.Set(key, val)
    
    return val, nil
}
```

### Query Optimization

```sql
-- Add indexes for common queries
CREATE INDEX idx_items_project_id ON items(project_id);
CREATE INDEX idx_items_created_at ON items(created_at DESC);
CREATE INDEX idx_links_source_id ON links(source_id);
CREATE INDEX idx_links_target_id ON links(target_id);

-- Composite indexes for common filters
CREATE INDEX idx_items_project_status ON items(project_id, status);

-- Vector index for semantic search
CREATE INDEX idx_items_embedding ON items USING ivfflat (embedding vector_cosine_ops);

-- Partial indexes for active items
CREATE INDEX idx_active_items ON items(project_id) WHERE deleted_at IS NULL;
```

### Connection Pooling

```go
// backend/internal/db/pool.go
type ConnectionPool struct {
    pool *pgxpool.Pool
}

func NewConnectionPool(dsn string) (*ConnectionPool, error) {
    config, err := pgxpool.ParseConfig(dsn)
    if err != nil {
        return nil, err
    }
    
    // Optimize pool settings
    config.MaxConns = 25
    config.MinConns = 5
    config.MaxConnLifetime = 5 * time.Minute
    config.MaxConnIdleTime = 1 * time.Minute
    
    pool, err := pgxpool.NewWithConfig(context.Background(), config)
    if err != nil {
        return nil, err
    }
    
    return &ConnectionPool{pool: pool}, nil
}
```

## 🔍 3. Monitoring & Observability

### Distributed Tracing

```go
// backend/internal/tracing/setup.go
func SetupTracing() (*sdktrace.TracerProvider, error) {
    exporter, err := jaeger.New(
        jaeger.WithCollectorEndpoint(
            jaeger.WithEndpoint("http://jaeger:14268/api/traces"),
        ),
    )
    if err != nil {
        return nil, err
    }
    
    tp := sdktrace.NewTracerProvider(
        sdktrace.WithBatcher(exporter),
        sdktrace.WithResource(resource.NewWithAttributes(
            semconv.ServiceNameKey.String("tracertm-api"),
        )),
    )
    
    otel.SetTracerProvider(tp)
    return tp, nil
}

// Usage in handlers
func (h *Handler) CreateItem(c echo.Context) error {
    tracer := otel.Tracer("tracertm")
    ctx, span := tracer.Start(c.Request().Context(), "CreateItem")
    defer span.End()
    
    span.SetAttributes(
        attribute.String("user.id", userID),
        attribute.String("project.id", projectID),
    )
    
    // ... handler logic
}
```

### Metrics Collection

```go
// backend/internal/metrics/setup.go
var (
    itemsCreated = prometheus.NewCounterVec(
        prometheus.CounterOpts{
            Name: "tracertm_items_created_total",
            Help: "Total items created",
        },
        []string{"project_id"},
    )
    
    linksCreated = prometheus.NewCounterVec(
        prometheus.CounterOpts{
            Name: "tracertm_links_created_total",
            Help: "Total links created",
        },
        []string{"link_type"},
    )
    
    apiLatency = prometheus.NewHistogramVec(
        prometheus.HistogramOpts{
            Name: "tracertm_api_latency_seconds",
            Help: "API latency in seconds",
        },
        []string{"method", "endpoint"},
    )
)
```

## 🚀 4. Cost Optimization (FinOps 2025)

### Cloud Cost Reduction

```yaml
# infrastructure/cost-optimization.yaml
# 1. Right-sizing
- Use spot instances for non-critical workloads
- Auto-scale based on metrics
- Use reserved instances for baseline

# 2. Resource optimization
- Enable compression for data transfer
- Use CDN for static assets
- Implement request batching

# 3. Monitoring
- Set up cost alerts
- Track cost per service
- Implement chargeback model
```

### Expected Savings
- Spot instances: 70% savings
- Reserved instances: 40% savings
- Optimization: 20-30% savings
- **Total potential: 40-50% cost reduction**

## 🔒 5. Data Security

### Encryption

```go
// backend/internal/crypto/encryption.go
type Encryptor struct {
    key []byte
}

func (e *Encryptor) Encrypt(plaintext string) (string, error) {
    block, err := aes.NewCipher(e.key)
    if err != nil {
        return "", err
    }
    
    gcm, err := cipher.NewGCM(block)
    if err != nil {
        return "", err
    }
    
    nonce := make([]byte, gcm.NonceSize())
    if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
        return "", err
    }
    
    ciphertext := gcm.Seal(nonce, nonce, []byte(plaintext), nil)
    return base64.StdEncoding.EncodeToString(ciphertext), nil
}
```

### Secrets Management

```go
// Use HashiCorp Vault
type VaultClient struct {
    client *api.Client
}

func (vc *VaultClient) GetSecret(path string) (map[string]interface{}, error) {
    secret, err := vc.client.Logical().Read(path)
    if err != nil {
        return nil, err
    }
    return secret.Data, nil
}
```

## ✅ IMPLEMENTATION CHECKLIST

- [ ] Implement Zero Trust middleware
- [ ] Setup OPA for ABAC
- [ ] Implement multi-level caching
- [ ] Add database indexes
- [ ] Setup connection pooling
- [ ] Implement distributed tracing
- [ ] Add Prometheus metrics
- [ ] Setup cost monitoring
- [ ] Implement encryption
- [ ] Setup Vault for secrets

## 📊 EFFORT vs BENEFIT

| Initiative | Effort | Benefit | Priority |
|-----------|--------|---------|----------|
| Zero Trust | 6 hrs | Very High | 🔥 Critical |
| Caching | 4 hrs | Very High | 🔥 Critical |
| Tracing | 4 hrs | High | ✅ High |
| Metrics | 3 hrs | High | ✅ High |
| Cost Optimization | 2 hrs | Very High | 🔥 Critical |

---

**Status:** Ready for implementation ✅

