Fight Caller ID Spoofing

STIR/SHAKEN (Secure Telephone Identity Revisited / Signature-based Handling of Asserted information using toKENs) autentifică caller ID pentru a preveni fraud.

How STIR/SHAKEN Works

Originating Carrier Signs Call

Creates cryptographic signature with attestation level (A, B, or C)

Signature Travels with Call

PASSporT token embedded in SIP Identity header

Terminating Carrier Verifies

Validates signature against certificate authority

Result Displayed to Callee

"Verified Caller" badge or spam warning

Attestation Levels

Full Attestation

Carrier verified caller identity AND their right to use the number.

✓ Known, authenticated customer
✓ Number assigned to customer
✓ Highest trust level

Partial Attestation

Carrier verified caller identity but NOT number ownership.

✓ Known, authenticated customer
⚠ Number not verifiable
• Common for ported numbers

Gateway Attestation

Carrier is just a gateway, cannot verify caller.

⚠ Unknown origin
⚠ Number not verifiable
• Higher spam risk

PASSporT Token Structure

// PASSporT (Personal Assertion Token) structure
{
  "header": {
    "alg": "ES256",
    "ppt": "shaken",
    "typ": "passport",
    "x5u": "https://cert.carrier.com/cert.pem"
  },
  "payload": {
    "attest": "A",           // Attestation level
    "dest": {
      "tn": ["+40722123456"] // Destination number
    },
    "iat": 1702041600,       // Issued at timestamp
    "orig": {
      "tn": "+40211234567"   // Originating number
    },
    "origid": "uuid-here"    // Unique call ID
  },
  "signature": "base64-signature..."
}

SIP Header Example

SIP/2.0 INVITE sip:+40722123456@sip.carrier.com
Via: SIP/2.0/UDP pbx.company.com:5060
From: "Kallina AI" <sip:+40211234567@pbx.company.com>
To: <sip:+40722123456@sip.carrier.com>
Identity: eyJhbGciOiJFUzI1NiIsInBwdCI6InNoYWtlbiIsIn...
Identity-Info: <https://cert.kallina.ai/stir.pem>;alg=ES256
Call-ID: 1234567890@pbx.company.com
CSeq: 1 INVITE
Content-Type: application/sdp

Implementation for Voice AI

Outbound Calls

1. Obtain STIR/SHAKEN certificate from CA
2. Configure your SBC to sign calls
3. Use registered numbers only
4. Aim for Attestation A
5. Monitor verification rates

Inbound Calls

1. Verify incoming PASSporT tokens
2. Check attestation level
3. Flag low-attestation calls
4. Apply fraud prevention rules
5. Log verification results

Verification Stats

94%

Calls Verified

Last 30 days

87%

Attestation A

Highest trust

Attestation B

Partial trust

Attestation C

Gateway only

Regulatory Requirements

Region	Status	Deadline
USA	Mandatory	June 30, 2021
Canada	Mandatory	November 30, 2021
EU (Romania)	In Progress	2024-2025
UK	Evaluating	TBD

Trusted Voice Identity

STIR/SHAKEN pentru caller ID de încredere.

Vezi Demo →

STIR/SHAKEN