Abstract: This invention discloses a method for displaying advertisements transmitted to a user unit, the method includes receiving, at the user unit, at least one advertisement tagged with a delay tag indicating whether display of the at least one advertisement can be delayed and only if the delay tag allows delaying display of the at least one advertisement, storing the at least one advertisement at the user unit, retrieving the at least one advertisement and displaying the at least one advertisement. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed.

Abstract: A method for hindering detection of information unintentionally leaked from a secret held in a memory unit is described, the method including receiving a triggering event waiting for at least a first amount of time to pass after the receipt of the triggering event, the memory unit being in a non-operational state during the at least a first amount of time after the at least a first amount of time has passed, changing at least one first condition under which the memory unit operates, thereby causing the memory unit to enter an operational state, waiting for a second amount of time to pass after the changing at least one first condition, and changing, after the second amount of time, at least one second condition under which the memory unit operates, thereby causing the memory unit to enter the non-operational state, wherein access to the secret information is enabled only during the second amount of time, and detection of secret information unintentionally leaked is limited during the first amount of time.

Abstract: A system and a method for providing variable security mechanisms for securing digital content, in which a single security mechanism is not used for all content. Instead, at least one characteristic or feature of the security mechanism is varied between units, instances or categories of content. Therefore, even if unauthorized access is gained to a single unit of content, the overall integrity and security of the system for content distribution is not compromised. Preferably, security is provided though a general mechanism, which is then varied in order to provide variable, dissimilar security schemes for different types of content. By “type of content”, it is meant any of a single unit of content, a single instance of content or a single category of content. For example, for a category of content, the content may be characterized according to the identity of the content itself, such as the title of a movie for example, and/or according to the owner of a particular copy of the content.

Abstract: This invention discloses a method for displaying advertisements transmitted to a user unit, the method includes receiving, at the user unit, at least one advertisement tagged with a delay tag indicating whether display of the at least one advertisement can be delayed and only if the delay tag allows delaying display of the at least one advertisement, storing the at least one advertisement at the user unit, retrieving the at least one advertisement and displaying the at least one advertisement. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed.

Abstract: This invention discloses a method for displaying advertisements transmitted to a user unit, the method includes receiving, at the user unit, at least one advertisement tagged with a delay tag indicating whether display of the at least one advertisement can be delayed and only if the delay tag allows delaying display of the at least one advertisement, storing the at least one advertisement at the user unit, retrieving the at least one advertisement and displaying the at least one advertisement. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed.

Abstract: This invention discloses a method for displaying advertisements transmitted to a user unit, the method includes receiving, at the user unit, at least one advertisement tagged with a delay tag indicating whether display of the at least one advertisement can be delayed and only if the delay tag allows delaying display of the at least one advertisement, storing the at least one advertisement at the user unit, retrieving the at least one advertisement and displaying the at least one advertisement. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed.

Abstract: A system and a method for providing variable security mechanisms for securing digital content, in which a single security mechanism is not used for all content. Instead, at least one characteristic or feature of the security mechanism is varied between units, instances or categories of content. Therefore, even if unauthorized access is gained to a single unit of content, the overall integrity and security of the system for content distribution is not compromised. Preferably, security is provided though a general mechanism, which is then varied in order to provide variable, dissimilar security schemes for different types of content. By “type of content”, it is meant any of a single unit of content, a single instance of content or a single category of content. For example, for a category of content, the content may be characterized according to the identity of the content itself, such as the title of a movie for example, and/or according to the owner of a particular copy of the content.

Abstract: A method for enforcing use of certificate revocation lists in validating certificates, the lists being associated with a series of list generation indices such that each list is assigned one index which advances according to a time of generation of the list, the lists and the indices being cryptographically signed, the method including receiving one of the lists and an associated index as an identifier of the one list, checking the certificates against the list, associating each of the certificates, which have been checked against the list, with the index, receiving an enforcement generation index (EGI) associated with a latest list in use, storing the EGI as a last known EGI, and refusing performance of an action associated with a certificate if the one index of the one certificate is earlier in the series than the last known EGI. Related apparatus and methods are also included.

Abstract: A system and a method for providing variable security mechanisms for securing digital content, in which a single security mechanism is not used for all content. Instead, at least one characteristic or feature of the security mechanism is varied between units, instances or categories of content. Therefore, even if unauthorized access is gained to a single unit of content, the overall integrity and security of the system for content distribution is not compromised. Preferably, security is provided through a general mechanism, which is then varied in order to provide variable, dissimilar security schemes for different types of content. By “type of content”, it is meant any of a single unit of content, a single instance of content or a single category of content. For example, for a category of content, the content may be characterized according to the identity of the content itself, such as the title of a movie for example, and/or according to the owner of a particular copy of the content.

Abstract: A system for scrambling/descrambling packets of a stream of content, each packet having a must stay clear (MSC) section, the system including an input handler including a receiving module to receive the stream, a characteristic analyzer to analyze the stream in order to determine a data independent characteristic of each packet, and a scrambling /descrambling device operationally associated with the input handler, the scrambling/descrambling device including a receiving module to receive the data independent characteristic for each packet from the input handler, and an Initial Value module to determine an Initial Value for each packet as a function of the data independent characteristic of one of the packets being processed, wherein the scrambling/descrambling device is adapted to scramble and/or descramble the packets based on the Initial Value and a Control Word. Related apparatus and methods are included.

Abstract: This invention discloses a method for displaying advertisements transmitted to a user unit, the method includes receiving, at the user unit, at least one advertisement tagged with a delay tag indicating whether display of the at least one advertisement can be delayed and only if the delay tag allows delaying display of the at least one advertisement, storing the at least one advertisement at the user unit, retrieving the at least one advertisement and displaying the at least one advertisement. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed.

Abstract: This invention discloses a method for displaying advertisements transmitted to a user unit, the method includes receiving, at the user unit, at least one advertisement tagged with a delay tag indicating whether display of the at least one advertisement can be delayed and only if the delay tag allows delaying display of the at least one advertisement, storing the at least one advertisement at the user unit, retrieving the at least one advertisement and displaying the at least one advertisement. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed.

Abstract: This invention discloses a method for displaying advertisements transmitted to a user unit, the method includes receiving, at the user unit, at least one advertisement tagged with a delay tag indicating whether display of the at least one advertisement can be delayed and only if the delay tag allows delaying display of the at least one advertisement, storing the at least one advertisement at the user unit, retrieving the at least one advertisement and displaying the at least one advertisement. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed.

Abstract: A method for determining proximity between a first device and a second device, the method comprising providing a first device storing a first device private key, the first device having an associated secure first device certificate storing secured information, the secured information comprising a first device public key corresponding to the first device private key, providing a second device storing a second device private key, the second device having an associated secure second device certificate storing secured information, the secured information comprising a second device public key corresponding to the second device private key, and a second device processing delay, providing a copy of the second device certificate to the first device, establishing a secure authenticated channel between the first device and the second device, sending a proximity challenge from the first device to the second device, the proximity challenge including a numeric challenge value, receiving the proximity challenge at the seco

Abstract: A method for producing a certificate, the certificate including data, the method including choosing a seed s, the seed s including a result of applying a function H to the data, generating a key pair (E,D), such that E=F(s,t), F being a publicly known function, and including s and t in the certificate. Related methods, and certificates produced by the various methods, are also described.

Abstract: A method for producing at least one ciphertext block from at least one plaintext block using a block cipher E and a key K, the method including receiving n plaintext blocks, wherein n is an integer greater than 0, setting Q0 equal to an initial value, and for each plaintext block of the n plaintext blocks: computing Qi=EK(Qi-1) XOR Pi; and computing Ci=M(Pi, Qi), thereby producing n ciphertext blocks, wherein 0<i?n, and Pi denotes an i-th plaintext block of the n plaintext blocks, and Ci denotes an i-th ciphertext block of the n ciphertext blocks, and M is a selector function which, for each bit Cij of block Ci, selects a first argument of M if bit Pij is not to be encrypted, and selects a second argument of M if bit Pij is to be encrypted. Related apparatus and methods are also provided.

Abstract: A system and a method for providing variable security mechanisms for securing digital content, in which a single security mechanism is not used for all content. Instead, at least one characteristic or feature of the security mechanism is varied between units, instances or categories of content Therefore, even if unauthorized access is gained to a single unit of content, the overall integrity and security of the system for content distribution is not compromised. Preferably, security is provided through a general mechanism, which is then varied in order to provide variable, dissimilar security schemes for different types of content. By “type of content”, it is meant any of a single unit of content, a single instance of content or a single category of content. For example, for a category of content, the content may be characterized according to the identity of the content itself, such as the title of a movie for example, and/or according to the owner of a particular copy of the content.

Abstract: A method for transforming content from a standard form coded in accordance with a standard coding scheme to content in a non-standard form coded in accordance with a non-standard coding scheme. The method includes providing content coded in a standard form in accordance with a standard coding scheme, the standard coding scheme including at least one syntax element; and altering the content coded in the standard form in accordance with a non-standard syntax modification scheme, thereby producing content encoded in a non-standard form in accordance with a non-standard coding scheme. Related apparatus and methods are also provided.

Abstract: This invention discloses a method for displaying advertisements transmitted to a user unit, the method includes receiving, at the user unit, at least one advertisement tagged with a delay tag indicating whether display of the at least one advertisement can be delayed and only if the delay tag allows delaying display of the at least one advertisement, storing the at least one advertisement at the user unit, retrieving the at least one advertisement and displaying the at least one advertisement. A billing system for reporting a commercial broadcast to a multiplicity of users is also disclosed.

Abstract: A system and a method for flexible, yet secure distribution of digital content items, optionally with an automatic payment mechanism for purchasing such content. The present invention supports the distribution of content to end user devices from a central distribution point (320), as in client-server models and variations thereof, and/or peer-to-peer distribution, for example between end user devices (310). In addition, the present invention also supports distribution models within either of these mechanisms for unitary distribution, to a specified end user device, or broadcast/multicast distribution, to a plurality of end user devices. In any case, in order for the distributed content to be operative, for example to be “played back” or otherwise displayed, the recipient end user device (310) must be in communication with a network control center (240).