Public key and protocol for an end-to-end encrypted card data request.
{"protocol":"rsa-oaep-aes-gcm-v1","publicKey":"-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA...\n-----END PUBLIC KEY-----","expiresAt":"2026-09-29T10:05:00Z"}