The ISMA Encryption and Authentication, Version 1.1 specification (or ISMACryp) specifies

encryption In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can dec ...

and message

authentication Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicat ...

services for

MPEG-4 MPEG-4 is a group of international standards for the compression of digital audio and visual data, multimedia systems, and file storage formats. It was originally introduced in late 1998 as a group of audio and video coding formats and related ...

over RTP streams. It was defined by the

Internet Streaming Media Alliance The Internet Streaming Media Alliance (ISMA) was a non-profit corporation founded in December 2000, by Apple Computer, Cisco Systems, Kasenna, Philips, and Sun Microsystems. Its stated mission was to accelerate the market adoption of open standards ...

and published on September 15, 2006. The ISMA Encryption and Authentication, Version 2.0 specifies content encryption, message authentication (integrity) services, an RTP payload format and a file format for pre-encrypted content for ISMA 1.0, ISMA 2.0 and more generally any media that can be stored as

elementary stream An elementary stream (ES) as defined by the MPEG communication protocol is usually the output of an audio encoder or video encoder. An ES contains only one kind of data (e.g. audio, video, or closed caption). An elementary stream is often referred ...

in an

ISO base media file format The ISO base media file format (ISOBMFF) is a container file format that defines a general structure for files that contain time-based multimedia data such as video and audio. It is standardized in ISO/ IEC 14496-12, a.k.a. MPEG-4 Part 12, and ...

(ISO/IEC 14496-12). The specification was published on 15 November 2007.ISMA (2007-11-15
ISMA Encryption and Authentication, Version 2.0
Retrieved on 2009-08-14 ISMACryp specification defined extensions over the ISO base media file format, which were registered by the registration authority for code-points in " MP4 Family" files.MP4 Registration Authorit
Registered Types - Brands
Retrieved on 2009-08-14 The ISMACryp 2.0 specification in an informative "Annex F" provides guidelines on how ISMACryp can be used together with the key and rights management system of

OMA DRM OMA DRM is a digital rights management (DRM) system invented by the Open Mobile Alliance, whose members represent mobile phone manufacturers (e.g. Nokia, LG, Motorola, Samsung, Sony-Ericsson, BenQ-Siemens), mobile system manufacturers (e.g. Er ...

v2 (

Open Mobile Alliance OMA SpecWorks, previously the Open Mobile Alliance (OMA), is a standards organization which develops open, international technical standards for the mobile phone industry. It is a nonprofit Non-governmental organization (NGO), not a formal governm ...

DRM DRM may refer to: Government, military and politics * Defense reform movement, U.S. campaign inspired by Col. John Boyd * Democratic Republic of Madagascar, a former socialist state (1975–1992) on Madagascar * Direction du renseignement militai ...

). The Packetized OMA DRM Content Format is almost based on ISMACryp format. There are two alternatives to ISMACryp, SRTP and

IPsec In computing, Internet Protocol Security (IPsec) is a secure network protocol suite that authenticates and encrypts packets of data to provide secure encrypted communication between two computers over an Internet Protocol network. It is used in ...

, that can also be used to provide service and content protection. The difference between the three is at what level encryption is done. Whereas ISMACryp encrypts MPEG-4 access units (that are in the RTP payload), SRTP encrypts the whole RTP payload, and IPsec encrypts packets at .

References

External links

ISMA Technical Specifications

DVB-H handheld video content protection with ISMA Encryption

OpenIPMP
- open source software for DRM including ISMACryp Cryptographic algorithms Television technology