/**

@page security_glossary Security glossary

\n

A glossary of security terms (mostly non-Symbian specific).

\n\n

@ref A, @ref B, @ref C, @ref D, @ref E, @ref F, @ref G, @ref H, @ref I, @ref J, @ref K, @ref L, @ref M, @ref N, @ref O, 

@ref P, @ref Q, @ref R, @ref S, @ref T, @ref U, @ref V, @ref W, @ref X, @ref Y, @ref Z

\n @anchor A \n

<table>

<tr><td><b>A</b></td><td></td></tr>

<tr><td>@anchor AES AES</td>

	<td>Advanced Encryption Standard -- The new conventional symmetric @ref block_cipher "block cipher" chosen by NIST as a 

	replacement for @ref DES. It can process 128-bit data blocks using 

	cipher keys with lengths of 128, 192, or 256 bits.</td></tr>

<tr><td>@anchor ASN ASN.1</td>

	<td>Abstract Syntax Notation 1 (See: <A HREF="http://asn1.elibel.tm.fr/en/introduction/index.htm">ASN.1</A>, 

	ISO/IEC 8824, and ISO/IEC 8825.) -- A data specification meta-language widely used in @ref public_key_cryptography "public key cryptography" 

	standards. (Also of interest: <A HREF="ftp://ftp.rsasecurity.com/pub/pkcs/doc/layman.doc">A Layman's Guide to 

	a Subset of ASN.1, BER, and DER</A>.)</td></tr>

<tr><td>@anchor asymmetric @anchor Asymmetric Asymmetric Cryptography</td>

	<td>A form of cryptography in which the 'key' is generated as a key pair: if one key is used for @ref encryption only the 

	other can be used to decrypt, and vice versa. \n\n

	Using asymmetric cryptography, the problem of key distribution becomes one of @ref authentication; i.e. how to make sure 

	that a given key really does belong to the entity that claims to own it. See:

	@li @ref asymmetric_cryptography

	@li @ref SS_Cryptalg_asymmetric_ciphers.</td></tr>

<tr><td>@anchor attribute_cert Attribute Certificate</td>

	<td>A digitally signed data structure including at least an identifier for an individual entity and a set of 

	attributes, whose function is to bind the entity with the attributes, usually for the purpose of authorisation. 

	</td></tr>

<tr><td>@anchor authentication @anchor Authentication Authentication</td>

	<td>Usually used to refer to a property of a communication; that the receiver of a message is able to ascertain its 

	origin, so an attacker cannot successfully impersonate the sender. </td></tr>

</table>\n @anchor B \n<table>

<tr><td><b>B</b></td><td></td></tr>

<tr><td>@anchor BER BER</td>

	<td>Basic Encoding Rules for @ref ASN "ASN.1", as defined in X.690. (Also of interest: 

	<A HREF="ftp://ftp.rsasecurity.com/pub/pkcs/doc/layman.doc">A Layman's Guide to a Subset of ASN.1, BER, and DER</A>.)

	</td></tr>

<tr><td>@anchor block_cipher Block Cipher</td>

	<td>A class of symmetric algorithm in which several bits of the input data are encrypted at once in a fixed-size 

	block. The cipher and its mode of operation define the block size: the @ref plaintext is split up into appropriately-sized 

	blocks and each block is fed into the cipher. </td></tr>

</table>\n @anchor C \n<table>

<tr><td><b>C</b></td><td></td></tr>

<tr><td>@anchor CA CA</td>

	<td>Certification Authority -- An organisation that performs the following functions in a hierachical @ref PKI: 

	@li	providing trusted @ref root_certificate "'root' certificates" to users (@ref EE "End Entities"), by supplying them with the CA's @ref public_key "public key" via 

		out-of-band means. 

	@li certifying End Entities (@ref EE "EE"s) by generating and distributing certificates for them. The certified @ref EE is the 

		subject of the @ref certificate; the CA is the issuer. The CA validates the certificate holder's identity and 'signs' 

		the @ref certificate so that it cannot be tampered with or forged. The @ref certificate issued by the CA binds a particular 

		@ref public_key "public key" to the name of the @ref EE the @ref certificate identifies.

	@li supporting certificate revocation and revocation checking: if an @ref EE suspects that their key has been compromised, 

		they can contact the CA that issued it, who will then revoke their @ref certificate.

	A CA will always have a root certificate-signing key pair that must be authenticated to End Entities via @ref out_of_band "out of band"

	channels. This key pair is not logically certified by anything, but it is usually distributed inside a self-signed 

	@ref certificate to afford some degree of tamper evidency. \n\n

	However, CAs do not have to use their root key pair to issue certificates directly to End Entities. For organizational 

	reasons and to reduce the exposure of keys, a CA may have a single root signing key pair, which it uses to certify a 

	set of subordinate key pairs that in turn are used to certify End Entities. Also, CAs may certify the signing keys 

	of other CAs by issuing cross certificates, which enable interoperation between two distinct @ref PKI "PKI"s.</td></tr>

<tr><td>@anchor CA_certificate CA Certificate 

	<td>A @ref certificate held by a @ref CA: the key pair associated with it is used for signing certificates issued by that 

	@ref CA. May or may not be self-signed.</td></tr>

<tr><td>@anchor CBC CBC</td>

	<td>Cipher Block Chaining -- A cryptographic mode for @ref block_cipher "block ciphers". It is an @ref encryption method that protects 

	against block replay attacks by making the encryption of a cipher block dependent on all blocks that precede it. 

	Before it is encrypted, the @ref plaintext is XORed with the previous @ref ciphertext block (which has been stored in a 

	feedback register). After the encryption, the resulting ciphertext is again stored in the feedback register, to 

	be XORed with the next plaintext block, and so on until the end of the message.</td></tr>

<tr><td>@anchor certificate @anchor certificates Certificate</td>

	<td>For our purposes, this is the same thing as a @ref public_key_certificate "public key certificate".</td></tr>

<tr><td>@anchor ciphermode Ciphermode</td>

	<td> description</td></tr>

<tr><td>@anchor ciphertext Ciphertext</td>

	<td>The output of an @ref encryption operation, or the input to a @ref decryption operation.</td></tr>

<tr><td>@anchor CLDC CLDC</td>

	<td><A HREF="http://java.sun.com/products/cldc/">J2ME Connected Limited Device Configuration</A> -- Serves the market consisting of personal, mobile, and 

	connected information devices. This configuration includes some new classes designed specifically to fit the 

	needs of small-footprint devices.</td></tr>

<tr><td>@anchor client_authentication Client Authentication</td>

	<td>In a secure client-server protocol such as @ref TLS, the process in which the client authenticates itself to 

	the server, so the server knows who it's talking to. \n See @ref WTLS_client_authentication "client authentication in WTLS". </td></tr>

<tr><td>Client/User/End Entity Certificate</td>

	<td>A @ref certificate issued by a @ref CA to an end entity, @ref EE, who may use it to demonstrate their 

	ownership of the key pair associated with it.</td></tr>  

<tr><td>@anchor CRL CRL</td>

	<td>Certificate Revocation List -- A list of (identifiers for) @ref certificates that have been revoked by a 

	particular @ref CA. The use of CRLs is for maintaining access to servers in a network, in a @ref PKI; in some cases, 

	@ref OCSP has superseded CRL. See:

	@li <A HREF="http://www.ietf.org/rfc/rfc2459.txt">RFC2459</A> 

	-- Internet @ref X509 "X.509" @ref PKI Certificate and CRL Profile 

	@li <A HREF="http://www.ietf.org/rfc/rfc3279.txt">RFC3279</A> 

	-- Algorithms and Identifiers for the Internet @ref X509 "X.509" @ref PKI Certificate and Certificate Revocation List 

	(@ref CRL) Profile

	@li <A HREF="http://www.ietf.org/rfc/rfc3280.txt">RFC3280</A> 

	-- Internet @ref X509 "X.509" @ref PKI Certificate and Certificate Revocation List (@ref CRL) Profile. 

	</td></tr>

<tr><td>@anchor cross_certificate Cross Certificate</td>

	<td>A @ref certificate issued by a @ref CA which certificates another @ref CA's @ref root_certificate "root certificate". This is way of uniting two distinct 

	certification hierarchies.</td></tr>  

</table>\n @anchor D \n<table>

<tr><td><b>D</b></td><td></td></tr>

<tr><td>@anchor decryption Decryption</td>

	<td>The process of turning encrypted data (called @ref ciphertext) into the original information (called 

	@ref plaintext) using a cryptographic algorithm parameterised with a key.</td></tr>  

<tr><td>@anchor DER DER</td>

	<td>Distinguished Encoding Rules -- A set of rules for encoding @ref ASN "ASN.1" data structures as a byte stream, which 

	has the property that any given @ref ASN "ASN.1" data structure will always encode to the same byte stream. DER is a 

	subset of @ref BER. (Also of interest: 

	<A HREF="ftp://ftp.rsasecurity.com/pub/pkcs/doc/layman.doc">A Layman's Guide to a Subset of ASN.1, BER, and DER</A>.)

	</td></tr>

<tr><td>@anchor DES DES</td>

	<td>Data Encryption Standard -- A symmetric @ref block_cipher "block cipher" (that is the U.S. and international standard) used for 

	@ref encryption and @ref decryption. A 64-bit block cipher with a 56-bit key organized as 16 rounds of operations. </td></tr>

<tr><td>@anchor digital_signature Digital Signature</td>

	<td>A structure linking some data and a @ref private_key "private key". A digital signature may be generated by the application of a 

	private key to some piece of data. The original data may be reconstructed by applying the corresponding @ref public_key "public key", 

	demonstrating that the signature could only have been generated by someone with access to the private key.\n\n

	Digital signatures have two primary uses: to demonstrate someone's identity by signing some challenge, as in 

	@ref client_authentication "client authentication" in @ref TLS, in which the client signs a @ref hash of the messages that have been exchanged; 

	and more strongly, for someone to demonstrate their acceptance of some human-processable information (e.g. 

	'Please withdraw £10,000 from my bank account') as in the @ref WMLScript Crypto API SignText function.\n\n

	See: an introduction to @ref Security_signatures.</td></tr>

<tr><td>@anchor DN DN</td>

	<td>Distinguished Name -- An @ref ASN "ASN.1" structure containing various attributes (name-value pairs) that together 

	uniquely identify the entity for certification purposes. \n\n

	The name used in @ref X509_certificate "X.509 certificates" is the X.500 Distinguished Name, which describes a path 

	through an X.500 Directory Information Tree. Conventionally, a DN comprises <i> at least </i> three attributes: a user's 

	name/ID (e.g., \c cn=Fred \c Bloggs), an organization name (e.g., \c o=Symbian \c UK \c Ltd), and a country designation 

	(e.g., \c c=GB ).

	</td></tr>

<tr><td>@anchor DSA DSA</td>

	<td>Digital Signature Algorithm -- A NIST-approved @ref asymmetric algorithm. It can only be used for generating 

	and verifying @ref digital_signature "digital signatures", not for @ref encryption. 

	See: The <A HREF="http://www.itl.nist.gov/fipspubs/fip186.htm">Digital Signature Standard</A>.

	</td></tr>

</table>\n @anchor E \n<table>

<tr><td><b>E</b></td><td></td></tr>

<tr><td>@anchor ECB ECB</td>

	<td>Electronic Codebook -- A cryptographic mode for @ref block_cipher "block ciphers". It is a mode that encrypts 

	blocks of @ref plaintext to corresponding blocks of @ref ciphertext. Given use of the same key, a block of plaintext 

	will always encrypt to the same block of ciphertext.</td></tr>

<tr><td>@anchor ECC ECC</td>

	<td>Elliptical Curve Cryptography -- An @ref asymmetric @ref encryption technique based on elliptic curve theory that 

	can be used to create faster, smaller, and more efficient cryptographic keys.</td></tr>

<tr><td>@anchor encryption Encryption</td>

	<td>The process of turning meaningful data (called @ref plaintext) into meaningless gibberish (called @ref ciphertext)

	using a cryptographic algorithm parameterised with a key.</td></tr>

<tr><td>@anchor EE EE</td>

	<td>End Entity -- A leaf node in a certification hierarchy: any entity in a @ref PKI which has a @ref certificate, but is

	not allowed to issue its own certificates.</td></tr>

</table>\n @anchor F \n<table>

<tr><td><b>F</b></td><td></td></tr>

</table>\n @anchor G \n<table>

<tr><td><b>G</b></td><td></td></tr>

</table>\n @anchor H \n<table>

<tr><td><b>H</b></td><td></td></tr>

<tr><td>@anchor hash Hash</td>

	<td>Hash algorithms take a variable-length input and produce a fixed length output known as a digest, or hash, of the 

	input. For cryptographic purposes they need to be one-way functions: it should not be possible to deduce the input 

	from the digest, or even any part of the input. Also, it should be hard to find collisions: that is, two different 

	inputs that produce the same output. See: 

	@li @ref cryptographic_hash

	@li @ref SS_Cryptalg_hash_algorithms.</td></tr>  

<tr><td>@anchor HMAC HMAC</td>

	<td>Keyed-Hashing for Message Authentication -- A mechanism for message @ref authentication using cryptographic hashes. It 

	can be used with any iterative cryptographic @ref hash function, e.g., @ref MD5, @ref SHA "SHA-1", in combination with a secret 

	shared key. The cryptographic strength of HMAC depends on the properties of the underlying @ref hash function.</td></tr>  

</table>\n @anchor I \n<table>

<tr><td><b>I</b></td><td></td></tr>

<tr><td>@anchor ICC ICC</td>

	<td>Integrated Circuit Card -- A removable card with at least data storage and sometimes processing.</td></tr>

<tr><td>@anchor IPSec IPSec</td>

	<td>IP Security Protocol -- A standard providing @ref secrecy and @ref authentication at the network or 

	datagram layer of network communication. IPSec is mandatory in IPv6. \n 

	See: <A HREF="http://www.ietf.org/html.charters/ipsec-charter.html">IPSec Working Group</A>.</td></tr>

</table>\n @anchor J \n<table>

<tr><td><b>J</b></td><td></td></tr>

</table>\n @anchor K \n<table>

<tr><td><b>K</b></td><td></td></tr>

</table>\n @anchor L \n<table>

<tr><td><b>L</b></td><td></td></tr>

</table>\n @anchor M \n<table>

<tr><td><b>M</b></td><td></td></tr>

<tr><td>@anchor MD2 MD2</td>

	<td>Legacy @ref hash algorithm. Considered insecure.</td></tr>

<tr><td>@anchor MD5 MD5</td>

	<td>Legacy @ref hash algorithm. Considered vulnerable.</td></tr>

<tr><td>@anchor message_digest_algorithm Message Digest Algorithm</td>

	<td>Same as a @ref hash algorithm. </td></tr>

<tr><td>@anchor MIDP MIDP</td>

	<td><A HREF="http://www.jcp.org/en/jsr/detail?id=118">Mobile Information Device Profile (JSP-118)</A>.

	-- A set of Java APIs that is generally implemented on the @ref CLDC "Connected Limited Device Configuration" (CLDC). 

	It provides a basic J2ME application runtime environment targeted at mobile information devices, such as 

	mobile phones and two-way pagers. The MIDP specification addresses issues such as user interface, persistent storage, 

	networking, and application model.</td></tr>

</table>\n @anchor N \n<table>

<tr><td><b>N</b></td><td></td></tr>

<tr><td>@anchor nonrepudiation Non-repudiation</td>

	<td>The process by which it is assured that an entity making a declaration cannot subsequently deny having made it: 

	so I can't claim that I never wrote that cheque. </td></tr>

</table>\n @anchor O \n<table>

<tr><td><b>O</b></td><td></td></tr>

<tr><td>@anchor OAEP OAEP</td>

	<td>Optimal Asymmetric Encryption Padding -- OAEP is a method for encoding messages, and addresses a potential 

	vulnerability in <A HREF="http://www.rsasecurity.com/rsalabs/pkcs/pkcs-1/index.html">PKCS#1</A>. Padding means extra 

	bits concatenated with a key, password, or @ref plaintext. @ref Padding helps against dictionary attacks.</td></tr>

<tr><td>@anchor OCSP OCSP</td>

	<td>@ref X509 "X.509" Internet Public Key Infrastructure Online Certificate Status Protocol -- A simple request/response 

	protocol. To establish whether a given @ref certificate or list of certificates has/have been revoked, a client forms an 

	OCSP request and sends this to an OCSP server. The server maintains revocation information in the form of, say, 

	Certificate Revocation Lists (@ref CRL "CRL"s). The server replies to the client with a signed OCSP response, stating for

	each certificate whether the status is Good, Revoked, or Unknown. This response in turn is checked to ensure that it

	is valid, and that it is from an entity trusted for performing revocation checking.

	See: 

	@li <A HREF="http://www.ietf.org/rfc/rfc2560.txt">RFC2560</A>

	-- @ref X509 "X.509" Internet @ref PKI Online Certificate Status Protocol - OCSP

	@li @ref overview_OCSP overview. </td></tr>

<tr><td>@anchor OID OID</td>

	<td>Object Identifier -- A universal constant uniquely associated with an object type used in @ref ASN "ASN.1".</td></tr>

<tr><td>@anchor OS OS Element</td>

	<td>A discrete, identifiable entity within a ROM file that implements a set of interfaces. Examples of 

	OS Elements include independently instantiable classes within DLLs, bitmaps within an MBM file, resource 

	entries within a resource file. An OS Element identifies a part of a ROM file that could in principle be 

	factored out or removed if it becomes architecturally advisable.</td></tr>

<tr><td>@anchor out_of_band Out Of Band</td>

	<td>A channel of communication that is distinct from the channel which we are using cryptography to try to secure, 

	and which is secure on its own terms; that is, its security is not dependent on the cryptography we are using. 

    A common example of an out of band channel is a motorcycle courier. 

 </td></tr>

</table>\n @anchor P \n<table>

<tr><td><b>P</b></td><td></td></tr>

<tr><td>@anchor Padding @anchor padding Padding</td>

	<td>Extending the size of a block of @ref plaintext to, say, a 64-bit block by addition of a regular or random pattern. 

	For example, for use with @ref ECB. See: 

	@li @ref rsa_padding

	@li @ref symmetric_ciphers.</td></tr>

<tr><td>@anchor PKCS PKCS</td>

	<td><A HREF="http://www.rsasecurity.com/rsalabs/pkcs/index.html">Public-Key Cryptography Standards</A>.</td></tr>

<tr><td><A HREF="http://www.rsasecurity.com/rsalabs/pkcs/pkcs-10/index.html">PKCS#10</A></td>

	<td>@ref PKI standard that describes how to construct @ref certificate requests.</td></tr>

<tr><td>@anchor PKG PKG file</td>

	<td>A text file that defines a @ref SIS file. The PKG file is passed to the MAKESIS tool to produce the 

	@ref SIS file.</td></tr>

<tr><td>@anchor PKI PKI</td>

	<td>Public Key Infrastructure -- A way of modelling real-world trust relationships that enables users of 

	@ref public_key_cryptography "public key cryptography" to have confidence in the ownership of the @ref public_key "public keys" they are using. A PKI consists of: 

	@li a trusted third party (@ref TTP)

	@li an @ref out_of_band "out of band" means of distributing the @ref TTP's @ref public_key_certificate "public key certificate" to @ref relying_party "relying parties"

	@li a means of distributing other certificates to @ref relying_party "relying parties"

	@li arrangements for the @ref revocation and renewal of these certificates 

	@li certificate management and validation software on the @ref relying_party "relying party's" computer 

	The TTP uses its signing key pair to create certificates for other entities, which relying parties can use to 

	authenticate these other entities. 

	We can classify PKIs according to whether they are hierachical or flat. In hierachical PKIs, such as the one defined

	in the PKIX set of standards, there is a distinction between users of the PKI such as End Entities (@ref EE "EE"s) and 

	@ref relying_party "relying parties", and entities responsible for issuing and distributing certificates such as @ref CA "CA"s and 

	@ref RA "RA"s. In a flat PKI such as the @ref web_of_trust "web of trust" underpinning @ref PGP, there are no entities whose sole role is

	to issue certificates; instead users of the PKI certify each other. </td></tr>

<tr><td>@anchor PKIX PKIX</td>

	<td>Public-Key Infrastructure (X.509) -- A profile of @ref X509 "X.509" for the internet. See: 

	@li @ref Certman_X509_Certificate_Validation

	@li <A HREF="http://www.ietf.org/rfc/rfc2459.txt">RFC2459</A> 

	-- Internet X.509 Public Key Infrastructure Certificate and CRL Profile.)</td></tr>

<tr><td>@anchor plaintext Plaintext</td>

	<td>The output of an @ref decryption operation, or the input to a @ref encryption operation.</td></tr>

<tr><td>@anchor PGP PGP</td>

	<td>Pretty Good Privacy -- A very widely-used @ref encryption and digital signing program.</td></tr> 

<tr><td>@anchor private_key Private Key</td>

	<td>In the context of @ref public_key_cryptography "public key cryptography", the private half of the key pair.</td></tr>

<tr><td>@anchor public_key Public Key</td>

	<td>In the context of @ref public_key_cryptography "public key cryptography", the public half of the key pair.</td></tr>

<tr><td>@anchor public_key_certificate Public Key Certificate</td>

	<td>A digitally signed structure including at least an identifier for an individual entity and a @ref public_key "public key", whose 

	function is to bind the entity with the key. </td></tr>

<tr><td>@anchor public_key_cryptography Public Key Cryptography</td>

	<td>A common application of @ref asymmetric cryptography in which one half of the key pair is kept secrect 

	(the @ref private_key "private key") and the other half is published (the @ref public_key "public key"). See:  

	@li @ref asymmetric_cryptography

	@li @ref Security_intro_PKC.</td></tr>

</table>\n @anchor Q \n<table>

<tr><td><b>Q</b></td><td></td></tr>

</table>\n @anchor R \n<table>

<tr><td><b>R</b></td><td></td></tr>

<tr><td>@anchor RA Registration Authority</td>

	<td>An organization responsible for registering new @ref certificate users in a @ref PKI, e.g. by gathering and verifying 

	information which identifies the @ref certificate applicant.</td></tr> 

<tr><td>@anchor revocation Revocation</td>

	<td>The term used for asserting that a @ref certificate is no longer valid: for example, because the @ref private_key "private key" 

	associated with it has been compromised.</td></tr>

<tr><td>@anchor relying_party Relying Party</td>

	<td>An entity who relies on the authenticity of a @ref public_key "public key".</td></tr>

<tr><td>@anchor root_certificate Root Certificate</td>

	<td>The @ref certificate of a @ref TTP "trusted third party". A certificate directly trusted by a @ref relying_party "relying party" 

	that is, trust in it is not established by cryptographic means, but trust in it is the prerequisite for establishing 

	trust in the entity which the relying party is trying to authenticate. Trust in a root certificate must be established

	through @ref out_of_band "out of band" means. A root certificate may or may not be self signed.\n\n

	See: @ref certman_certstore_root_cert_management.</td></tr> 

<tr><td>@anchor RSA <A HREF="http://www.rsasecurity.com/rsalabs/rsa_algorithm/index.html">RSA</A></td>

	<td>A @ref public_key "public key" algorithm used for both @ref encryption and @ref digital_signature "digital signatures", named after its creators: 

	Rivest, Shamir, and Adleman.</td></tr>

</table>\n @anchor S \n<table>

<tr><td><b>S</b></td><td></td></tr>

<tr><td>@anchor secrecy Secrecy</td>

	<td>This means that access to information is controlled: for example, it means that two entities (e.g. people, 

	machines, processes) are able to communicate with one another without any other entities being able to access the 

	information communicated, or that an entity may store some information and be assured that only this entity will be 

	able to access it.</td></tr>  

<tr><td>@anchor SHA SHA-1</td>

	<td>Secure Hash Algorithm 1 -- A widely used @ref hash algorithm, producing a 160-bit digest.  </td></tr>

<tr><td>@anchor server_authentication Server Authentication</td>

	<td>In a secure client-server protocol such as @ref TLS, the process in which the server authenticates itself to the 

	client, so the client knows to whom it's talking. \n See: @ref WTLS_server_authentication "Server authentication in WTLS".</td></tr>

<tr><td>@anchor SignText SignText</td>

	<td>A function defined in the @ref WMLScript Crypto API that provides application-level @ref authentication and 

	@ref nonrepudiation "non-repudiation" for transactions. </td></tr>

<tr><td>@anchor SIS SIS file</td>

	<td>A binary package file containing all the files for an installation, as well as metadata describing which 

	directory to install them into, dependencies, etc..\n

	See: @ref overview_SWI overview.</td></tr>

<tr><td>@anchor Stub SIS Stub file</td>

	<td>A @ref SIS file containing only the metadata, and not the files. After the installation, this file is archived 

	on the device for uninstallation purposes, etc..</td></tr>

<tr><td>@anchor SMIME S/MIME</td>

	<td><A HREF="http://www.ietf.org/html.charters/smime-charter.html">Secure/Multipurpose Internet Mail Extensions</A> 

	-- Provides a consistent way to send and receive secure MIME data. S/MIME provides the following cryptographic 

	security services for electronic messaging applications: @ref authentication, message integrity and @ref nonrepudiation "non-repudiation" of 

	origin (using @ref digital_signature "digital signatures") and privacy and data security (using @ref encryption); see 

	<A HREF="http://www.ietf.org/rfc/rfc2633.txt">RFC2633</A> -- S/MIME Version 3 Message Specification.

	</td></tr>

<tr><td>@anchor SSL SSL</td>

	<td>Secure Sockets Layer -- A protocol for securing network	connections that provides @ref authentication, @ref encryption, and 

	data integrity using @ref PKI "Public Key Infrastructure" (PKI). Precursor to @ref TLS. SSL has been through three versions: 

	the first two are considered insecure, and the third is almost identical to @ref TLS.</td></tr>

<tr><td>@anchor stream_cipher Stream Cipher</td>

	<td>A class of symmetric algorithm that is initialised with a key, then outputs a stream of pseudorandom bits. 

	This 'keystream' is typically XOR-ed with the @ref plaintext to generate the @ref ciphertext. So they encrypt a bit of 

	plaintext at a time. </td></tr>

<tr><td>@anchor symmetric_cryptography Symmetric Cryptography</td>

	<td>A form of cryptography in which the same key is used for @ref encryption and @ref decryption.\n\n 

	Symmetric cryptography is fast, but suffers from the problem of how to distribute the key privately. @ref Asymmetric 

	cryptography is an attempt to alleviate the key distribution problem, by reducing the requirement for the distributed 

	key from one of privacy to one of @ref authentication. See:

	@li @ref symmetric_ciphers

	@li @ref SS_Cryptalg_symmetric_ciphers.</td></tr>

</table>\n @anchor T \n<table>

<tr><td><b>T</b></td><td></td></tr>

<tr><td>@anchor TLS TLS</td>

	<td>Transport Layer Security -- A protocol that provides communications secrecy, and optionally @ref authentication, 

	over the Internet TCP/IP. The protocol allows client/server applications to communicate in a way that is designed to 

	prevent eavesdropping, tampering, or message forgery.

	In this protocol a client connects to a server; the two then perform a handshake in which they exchange a 

	symmetric key by using @ref asymmetric cryptography, which is then used to encrypt their communications, 

	providing the @ref secrecy element. Without the @ref authentication element, @ref secrecy is not very useful; although 

	only client and server can understand the data exchanged, the client doesn't know who the server is or vice versa. TLS 

	provides the capability for @ref WTLS_server_authentication "server authentication", in which the client establishes who the server is, and 

	@ref client_authentication "client authentication" in which the server establishes who the client is. \n\n

	See: <A HREF="http://www.ietf.org/rfc/rfc2246.txt">RFC2246</A> --

	The TLS Protocol). TLS is the successor to the @ref SSL "Secure Sockets Layer" (SSL). (Also, see: @ref WTLS.)</td></tr>

<tr><td>@anchor TTP TTP</td>

	<td>Trusted Third Party -- An entity whose @ref public_key "public key" is known to a @ref relying_party "relying party" due to its having been received 

	via @ref out_of_band "out of band" means, and which is trusted to issue @ref public_key_certificate "public key certificates" for other entities not directly 

	known to the relying party. A @ref CA is a type of TTP. </td></tr>

</table>\n @anchor U \n<table>

<tr><td><b>U</b></td><td></td></tr>

<tr><td>@anchor URI URI</td>

	<td>Uniform Resource Identifier -- A way to identify some content on the Internet, typically through the use of an 

	identifier for the scheme (e.g. HTTP) through which the content may be accessed, and an identifier for the 

	content that makes sense within that scheme. 

	The most common form of URI is a Web page address, which is a particular form or subset of URI called a Uniform 

	Resource Locator (URL).</td></tr>