Japan-based bitcoin exchange Mt. Gox has announced some new updates and features to its platform including a one-time password (OTP) card.

This battery-powered password generator is linked to a user's account, and can be used for an additional layer of security, either by storing a unique password or generating a new one every time a user performs actions such as logging in or initiating a withdrawal online.

The card costs $39.99 and is shipping now. For more information about the Mt. Gox OTP card, the exchange has produced a resource guide.

Mt. Gox has also announced increased SEPA withdrawal limits from its European bank, based in Poland. No exact amount is specified, only that the bank has "doubled our limit," according to the exchange's press release.

Additionally, a modified trading interface has been released. Earlier this year, Mt. Gox had announced it was partnering with Akamai in order to speed up its performance. This new update appears to be more on the cosmetic side; with color indicators for buy and sell actions and more details regarding transaction fees at the time of a trade.

The exchange also is now requiring all BTC transfers to pay a 0.001 BTC network fee. Previously, Mt. Gox only required this to speed up transaction times from one bitcoin wallet to another.

One of the earliest exchange sources for obtaining bitcoins and at one time this year the largest, Mt. Gox has been riddled with problematic issues. The gamut ranges from DDoS attacks, banking delays and even the seizure of some of its funds by the US government.

Some of these problems have caused Mt. Gox to tumble from its number one bitcoin exchange ranking, a spot currently owned by BTC China.

Mt. Gox has also announced that for Black Friday, and through to Cyber Monday at the beginning of next week, there will be no transaction fees for buying or selling bitcoins on its platform.