A method for securely storing a private value, the method using a system comprising: a mobile storage device having an identifying parameter, the mobile storage device comprising a first wireless communications interface configured to establish a local proximity wireless connection; and a virtual safe device configured to carry out cryptographic functions, the virtual safe device comprising: a second wireless communications interface configured to establish a local proximity wireless connection; a security module; and a secure memory comprising a secret key corresponding to the identifying parameter of the at least one mobile storage device, said secret key having been generated by the virtual safe device; the mobile storage device storing a public key associated with the security module; the method comprising: establishing a local proximity wireless communication channel (SWIF) between the first wireless communications interface and the second wireless communications interface; sending the identifying parameter from the mobile storage device to the virtual safe device via the local proximity wireless communication channel (SWIF); sending the private value from the mobile storage device to the virtual safe device via the local proximity wireless communication channel (SWIF); encrypting, by the security module, the private value using the secret key corresponding to the identifying parameter of the mobile storage device to give the encrypted version of the private value; and sending the encrypted version of the private value from the virtual safe device for said secure storage of the private value to be made on the mobile storage device. a mobile storage device having an identifying parameter, the mobile storage device comprising a first wireless communications interface configured to establish a local proximity wireless connection; and a virtual safe device configured to carry out cryptographic functions, the virtual safe device comprising: a second wireless communications interface configured to establish a local proximity wireless connection; a security module; and a secure memory comprising a secret key corresponding to the identifying parameter of the at least one mobile storage device, said secret key having been generated by the virtual safe device; a second wireless communications interface configured to establish a local proximity wireless connection; a security module; and a secure memory comprising a secret key corresponding to the identifying parameter of the at least one mobile storage device, said secret key having been generated by the virtual safe device; the mobile storage device storing a public key associated with the security module; the method comprising: establishing a local proximity wireless communication channel (SWIF) between the first wireless communications interface and the second wireless communications interface; sending the identifying parameter from the mobile storage device to the virtual safe device via the local proximity wireless communication channel (SWIF); sending the private value from the mobile storage device to the virtual safe device via the local proximity wireless communication channel (SWIF); encrypting, by the security module, the private value using the secret key corresponding to the identifying parameter of the mobile storage device to give the encrypted version of the private value; and sending the encrypted version of the private value from the virtual safe device for said secure storage of the private value to be made on the mobile storage device. establishing a local proximity wireless communication channel (SWIF) between the first wireless communications interface and the second wireless communications interface; sending the identifying parameter from the mobile storage device to the virtual safe device via the local proximity wireless communication channel (SWIF); sending the private value from the mobile storage device to the virtual safe device via the local proximity wireless communication channel (SWIF); encrypting, by the security module, the private value using the secret key corresponding to the identifying parameter of the mobile storage device to give the encrypted version of the private value; and sending the encrypted version of the private value from the virtual safe device for said secure storage of the private value to be made on the mobile storage device.