Voice data is not standard business data. It is personal data in its most sensitive form- biometric by nature, legally regulated in most jurisdictions, and carrying information that callers did not explicitly choose to type into a form field.
A 2025 healthcare provider voice AI audit failure resulted in a $2.3 million HIPAA fine because call recordings were retained for 90 days instead of the required 30-day window. The system was shut down for three weeks. The security controls existed on paper. Automated enforcement did not.
Secure voice data architecture means controls that are live and verifiable at every stage- not documented in a policy and manually administered. Here is how Sicada's controls stack operates.
Encryption Controls
Encryption is the foundational layer of voice AI security. Voice data passes through multiple systems between capture and storage- telephony endpoint, STT processor, LLM inference layer, TTS synthesis, and CRM write-back and must be protected at every handoff.
In Transit
- All voice streams between the caller's telephony endpoint and Sicada's processing infrastructure are encrypted using TLS 1.3- the current minimum standard for data in transit
- Audio data transmitted between Sicada's STT layer, LLM inference layer, and TTS synthesis layer uses the same TLS 1.3 standard- no plaintext transmission between internal processing components
- For high-sensitivity deployments in healthcare and financial services, end-to-end encryption is available- ensuring that audio is never accessible in plaintext to any intermediate processing layer
At Rest
- All stored call recordings are encrypted using AES-256- the current industry standard for data at rest
- Transcripts and CRM write-back data are encrypted at the field level, not just at the storage volume level
- Encryption keys are managed through a dedicated Key Management Service- keys are rotated on a defined schedule and are never stored alongside the data they protect
- Backups of voice data are encrypted with the same AES-256 standard as primary storage
Access Controls
Voice data access is governed by a role-based access control framework built on the principle of least privilege- every user and service account has the minimum access required to perform their function, and nothing more.
Role-Based Access Control
- Access roles are defined at deployment and reviewed quarterly- a support technician reviewing call quality does not have the same access as a platform administrator
- Production voice data requires explicit access grants- developer access to production recordings is not inherited from general platform access
- Service accounts used by integrations- CRM connectors, analytics tools, compliance platforms are scoped to the specific objects and fields they need to read or write, not granted broad API access
Authentication
- Multi-factor authentication is required for all administrative console and API access
- Session tokens expire on defined inactivity thresholds no persistent sessions for voice data access
- API keys for integration access are rotatable and can be revoked immediately without service disruption
Environment Isolation
- Customer data is isolated at the environment level- no cross-tenant data access is architecturally possible
- Development and staging environments do not have access to production voice data
- Where custom model training requires data samples, training environments are air-gapped from production storage
Audit Logs
Every access to voice data- every playback, every transcript read, every API call, every deletion event is logged with a complete record that supports both internal governance and regulatory audit requirements.
What Is Logged
- User ID or service account identifier
- Timestamp of the access event to millisecond precision
- Action type- read, write, delete, export, API query
- Data object accessed- specific recording ID, transcript ID, or CRM record
- IP address and session identifier for human access events
- Outcome- successful access, denied access, or error
How Logs Are Protected
- Audit logs are written to immutable storage- they cannot be modified or deleted by any user, including platform administrators
- Logs themselves are encrypted and access-controlled- access to audit logs requires a separate role grant from access to voice data
- Log retention periods are configured to match the regulatory requirements of each deployment- HIPAA deployments retain audit logs for six years; GDPR deployments retain for the period proportionate to the processing purpose
- Anomalous access patterns- bulk downloads, access from unusual IP ranges, access outside business hours on sensitive data- trigger automated alerts to the designated security contact
PII Redaction and Data Minimisation
Not all voice data needs to be stored in full. For deployments where recordings are not required for operational or regulatory purposes, Sicada supports real-time PII redaction before storage.
- Payment card numbers spoken during calls are detected and redacted from transcripts in real time- PCI DSS compliant configurations do not store card data in any form
- Government ID numbers, social security numbers, and health identifiers can be redacted from transcripts before storage while retaining the qualification and intent data the CRM workflow requires
- Zero-retention configurations process the call and write structured output to CRM without persisting any audio recording or transcript- appropriate for deployments where the regulatory cost of storing audio outweighs the operational benefit.
Compliance Framework Coverage
Sicada's voice data security controls are designed to support compliance with the following frameworks. Buyers in regulated industries should request a copy of the relevant compliance documentation before deployment:
GDPR- Data minimisation, purpose limitation, right to erasure, cross-border transfer controls via Standard Contractual Clauses, and mandatory DPIA documentation for high-risk deployments
HIPAA- Business Associate Agreement availability, PHI handling controls, AES-256 encryption, six-year audit log retention, breach notification procedures
SOC 2 Type II- Annual third-party audit covering Security, Confidentiality, Availability, Processing Integrity, and Privacy trust service criteria
PCI DSS- Real-time card number redaction, no storage of full card data in voice recordings or transcripts, scoped cardholder data environment
DPDP Act (India)- Consent logging with auditable timestamp records, data minimisation, deletion on purpose fulfilment, and data principal rights management
PDPL (UAE and Saudi Arabia)- Regional data processing and storage, data localisation compliance, proportionate retention, and individual deletion rights
Security Controls Checklist at a Glance
Encryption
- TLS 1.3 for all voice data in transit
- AES-256 for all recordings and transcripts at rest
- Field-level encryption for CRM write-back data
- Key Management Service with scheduled rotation
- End-to-end encryption available for high-sensitivity deployments
Access Controls
- Role-based access control on least-privilege model
- MFA required for all admin and API access
- Quarterly access permission reviews
- Environment isolation- no cross-tenant or dev-to-prod access
- Scoped service account permissions for all integrations
Audit Logging
- Immutable audit log on every data access event
- Full record: user, timestamp, action, object, outcome
- Anomalous access pattern alerting
- Configurable retention matching regulatory requirements
- Encrypted, access-controlled log storage
Data Minimisation
- Real-time PII redaction for payment and government ID data
- Zero-retention configuration available
- Configurable retention windows with automated verified deletion
- Backup encryption matching primary storage standard
What to Ask Sicada Before Deployment
Before finalising any deployment involving personal voice data, confirm the following in writing:
- Is a current SOC 2 Type II report available for review?
- Will Sicada sign a Data Processing Agreement and, where applicable, a Business Associate Agreement?
- Where is voice data physically stored and does that geography meet your data localisation requirements?
- Is real-time PII redaction available for your specific data categories?
- What is the incident response SLA and notification timeline in the event of a data breach?
These are not optional questions for regulated industries. They are the baseline due diligence that any data protection officer or security team will require before approving a voice AI deployment.
Contact Sicada's team to request compliance documentation and discuss the security configuration that applies to your deployment.
Frequently Asked Questions
How does Sicada encrypt voice data?
Sicada encrypts voice data in transit using TLS 1.3 and at rest using AES-256. Encryption keys are managed through a dedicated Key Management Service with scheduled rotation. End-to-end encryption is available for high-sensitivity deployments where plaintext audio must not be accessible to any intermediate processing layer.
What access controls does Sicada apply to voice recordings?
Sicada applies role-based access control on a least-privilege model- every user and service account has the minimum access required for their function. Multi-factor authentication is required for all administrative and API access. Production voice data requires explicit access grants separate from general platform access.
What is logged in Sicada's voice AI audit trail?
Every access to voice data is logged with user ID, timestamp, action type, data object accessed, IP address, and outcome. Logs are written to immutable storage, encrypted, and retained for the period required by the regulatory framework applicable to each deployment.
Is Sicada HIPAA and GDPR compliant for voice data?
Sicada's security controls are designed to support HIPAA and GDPR compliance- including BAA availability for HIPAA deployments, AES-256 encryption, six-year audit log retention, real-time PHI redaction, and GDPR data minimisation and erasure controls. Compliance documentation is available on request from the Sicada team.
