kCFStreamSocketSecurityLevelNone Specifies that no security level be set. Declarationlet kCFStreamSocketSecurityLevelNone: CFString See AlsoConstantskCFStreamSocketSecurityLevelSSLv2kCFStreamSocketSecurityLevelSSLv3kCFStreamSocketSecurityLevelTLSv1kCFStreamSocketSecurityLevelNegotiatedSSL