1.1 Glossary

This document uses the following terms:

Advanced Encryption Standard (AES): A block cipher that supersedes the Data Encryption Standard (DES). AES can be used to protect electronic data. The AES algorithm can be used to encrypt (encipher) and decrypt (decipher) information. Encryption converts data to an unintelligible form called ciphertext; decrypting the ciphertext converts the data back into its original form, called plaintext. AES is used in symmetric-key cryptography, meaning that the same key is used for the encryption and decryption operations. It is also a block cipher, meaning that it operates on fixed-size blocks of plaintext and ciphertext, and requires the size of the plaintext as well as the ciphertext to be an exact multiple of this block size. AES is also known as the Rijndael symmetric encryption algorithm [FIPS197].

authentication: The ability of one entity to determine the identity of another entity.

base64 encoding: A binary-to-text encoding scheme whereby an arbitrary sequence of bytes is converted to a sequence of printable ASCII characters, as described in [RFC4648].

Beacon: A management frame that contains all of the information required to connect to a network. In a WLAN, Beacon frames are periodically transmitted to announce the presence of the network.

big-endian: Multiple-byte values that are byte-ordered with the most significant byte stored in the memory location with the lowest address.

Bluetooth (BT): A wireless technology standard which is managed by the Bluetooth Special Interest Group and that is used for exchanging data over short distances between mobile and fixed devices.

Bluetooth Low Energy (BLE): A low energy version of Bluetooth that was added with Bluetooth 4.0 to enable short burst, short range communication that preserves power but allows proximal devices to communicate.

cipher block chaining (CBC): A method of encrypting multiple blocks of plaintext with a block cipher such that each ciphertext block is dependent on all previously processed plaintext blocks. In the CBC mode of operation, the first block of plaintext is XOR'd with an Initialization Vector (IV). Each subsequent block of plaintext is XOR'd with the previously generated ciphertext block before encryption with the underlying block cipher. To prevent certain attacks, the IV has to be unpredictable, and no IV is used more than once with the same key. CBC is specified in [SP800-38A] section 6.2.

encryption: In cryptography, the process of obscuring information to make it unreadable without special knowledge.

Hash-based Message Authentication Code (HMAC): A mechanism for message authentication using cryptographic hash functions. HMAC can be used with any iterative cryptographic hash function (for example, MD5 and SHA-1) in combination with a secret shared key. The cryptographic strength of HMAC depends on the properties of the underlying hash function.

initialization vector: A data block that some modes of the AES cipher block operation require as an additional initial data input. For more information, see [SP800-38A].

key: In cryptography, a generic term used to refer to cryptographic data that is used to initialize a cryptographic algorithm. Keys are also sometimes referred to as keying material.

Media Access Control (MAC) address: A hardware address provided by the network interface vendor that uniquely identifies each interface on a physical network for communication with other interfaces, as specified in [IEEE802.3]. It is used by the media access control sublayer of the data link layer of a network connection.

Microsoft Account: A credential for Windows devices and Microsoft services used to sign in users and connect all of their Microsoft-related products.

private key: One of a pair of keys used in public-key cryptography. The private key is kept secret and is used to decrypt data that has been encrypted with the corresponding public key. For an introduction to this concept, see [CRYPTO] section 1.8 and [IEEE1363] section 3.1.

public key: One of a pair of keys used in public-key cryptography. The public key is distributed freely and published as part of a digital certificate. For an introduction to this concept, see [CRYPTO] section 1.8 and [IEEE1363] section 3.1.

salt: An additional random quantity, specified as input to an encryption function that is used to increase the strength of the encryption.

session key: A relatively short-lived symmetric key (a cryptographic key negotiated by the client and the server based on a shared secret). A session key's lifespan is bounded by the session to which it is associated. A session key has to be strong enough to withstand cryptanalysis for the lifespan of the session.

SHA-256: An algorithm that generates a 256-bit hash value from an arbitrary amount of input data.

TCP/IP: A set of networking protocols that is widely used on the Internet and provides communications across interconnected networks of computers with diverse hardware architectures and various operating systems. It includes standards for how computers communicate and conventions for connecting networks and routing traffic.

thumbprint: A hash value computed over a datum.

Uniform Resource Identifier (URI): A string that identifies a resource. The URI is an addressing mechanism defined in Internet Engineering Task Force (IETF) Uniform Resource Identifier (URI): Generic Syntax [RFC3986].

User Datagram Protocol (UDP): The connectionless protocol within TCP/IP that corresponds to the transport layer in the ISO/OSI reference model.

UTF-8: A byte-oriented standard for encoding Unicode characters, defined in the Unicode standard. Unless specified otherwise, this term refers to the UTF-8 encoding form specified in [UNICODE5.0.0/2007] section 3.9.

web service: A service offered by a server to other devices, to allow communication over the web.

Wi-Fi Direct: A peer-to-peer device connectivity technology that enables high-bandwidth sharing of media and content between devices without requiring an Internet connection or wireless router. Wi-Fi Direct provides essentially the same service to end users that Bluetooth does, but it is faster and allows devices to be farther apart when communicating.

MAY, SHOULD, MUST, SHOULD NOT, MUST NOT: These terms (in all caps) are used as defined in [RFC2119]. All statements of optional behavior use either MAY, SHOULD, or SHOULD NOT.